Nature's Generator Platinum PE System 1800W + 3x 100W Solar Panel + 1x Power Pod + 1x Power Transfer Solar Generator Kit

Our Nature's Generator Platinum-PE System brings together our Nature's Generator Platinum System and the Power Transfer Kit.
The Nature's Generator Platinum System is a system that allows you to generate and store extended power. With the addition of the Power Transfer Kit you'll be able to link the existing power circuits in your indoor breaker panel to your Nature's Generator Platinum System. You'll have the ability to continue providing power to your most needed items without having to disconnect them from their current outlets.
The Nature's Generator Platinum System provides a combined 1,920W hours of run time and with the included three 100W Nature's Power Panels you can continually use and recharge your system.
*Some assembly required for Power Panels.
Nature's Generator Platinum System PE Highlights
- Extend your run time and energy storage capacity with a combined 1,920Wh of run time by daisy-chaining the Nature's Generator Power Pod to the Nature's Generator.
- Continually recharge the Nature's Generator and Power Pod while in use, using the included Nature's Generator Power Panels.
- The Nature's Generator Power Transfer Kit can be installed next to almost any indoor breaker panel. By connecting your Nature's Generator to the Power Transfer Kit you'll more easily be able to continue providing power to your most needed items in case of power loss.
Get To Know Your Nature's Generator
Front Panel Ports
- 3 x 120-Volt AC outlet (1800 watt max)
- 2 x USB port(UP TO 3A Combined power)
- 1 x 12-Volt DC outlet
- 1 x 300-Watt Wind input
- 1 x 200-Watt Solar input
- 1 x 90-Watt Wall Charging input
Other Port At The Back
- Expansion Port: 175A Anderson Power Pole
- Expansion Port Fuse: 200A
LCD Display: LCD display shows the information of the system. LCD Display Button: Press it to light up LCD display for 30 seconds.
Get To Know Your Nature's Generator Power Pod
Front Panel
- One 12V DC port (240W max)
- Solar Input (200W Max)
- LED multi-color battery fuel gauge
- Expansion Cord to connect to a Nature's Generator or Power Pod - 45in. Long
- Type: AGM Sealed Lead Acid
- Capacity: 100Ah (1,200Wh)
- Built-in charge controller
- Built-in low battery protection
- Expansion port: Anderson Power Pole
Keep plugged in or recharge every 2-3 months of non-use
The Nature's Generator Power Pod also includes a compartment on the top section of the product. The fuse connector for expansion purposes is stored here. You can also store any other items inside the compartment that you may want to keep handy with your unit.
Get To Know Your Nature's Generator Solar Panel
- Rated 100-watts power panel
- Daisy-Chainable to another solar panel using MC4 branch connector
- Includes multiple positions (summer/winter) for optimum sun exposure
- Reinforced with 3.2mm safety, anti-reflective glass
- Included cable management system and wheels for mobility
- Heavy duty anodized durable aluminum frame
- Includes eye bolts for securing the power panel to different surfaces
*Stand and Wheels kit will be provided for free upon request. Some assembly required.
Get To Know Your Nature's Generator Power Transfer Kit
As the Power Transfer Kit links Nature's Generator to the existing power lines in your indoor breaker panel, you can continue providing power without having to move big items like your refrigerator or getting into tight corners to unplug devices from your wall.
How to Use
- Fit the female connector of the included power cord into the power inlet of your Power Transfer Switch.
- Insert the male plug into any of the AC outlets on the Nature's Generator.
Common Circuits to Keep Backed Up
- Lights
- Garage Doors
- Refrigerators/Freezers
- Common areas
*Important: Installation of the Power Transfer Kit must be performed by a qualified electrician in compliance with all applicable electrical codes. Do not charge Nature's Generator by wall through AC input port when using Power Transfer Kit.
Specifications
- SKU: HKNGPTPE
Nature's Generator
Inverter
- Output Power: 1800 watt max / 1440 watt continuous /2880 watt peak
- Pure sine wave
- Output voltage: 120V
- Output frequency: 60Hz
Battery
- Type: AGM Sealed Lead Acid
- Capacity: 12V 60Ah (720Wh)
- Keep plugged in or recharge every 4 months of non-use
- Built-in charge controller
- Built-in low battery protection
Ports
- USB Port: 5V, up to 3A (15W)
- 12V DC Port: up to 20A (240W max)
- Expansion Port: 200A fuse
Chargers
- AC Charger: 90W
- AC Charger Indicator: red (charging) and green (charged)
- Solar Charger: 200watt
- Wind Charger: 300watt
General
- 18 x 12 x 15 in (47 x 30 x 38 cm) without cart
- 23 × 17 × 22 in ( 57 × 42 × 55 cm) with cart
- Operating temperature: 32-104 °F (0-40 °C)
- Storage Temperature: 23–111 °F (-5–45 °C)
- Weight: 83 lbs (37.6 kg)
Nature's Generator Power Pod
- Type: AGM Sealed Lead Acid
- Capacity: 100Ah (1,200Wh)
- One 12V DC port (240W max)
- Solar Input (200W Max)
- LED multi-color battery fuel guage
- Expansion Cord to connect to a Nature's Generator or Power Pod - 35in. Long
- Keep plugged in or recharge every 4 months of non-use
General
- Power Pod Dimension: 18 x 12 x 15 in.
- Weight out of box: 92 lbs
- Operating temperature: 32-104 °F (0-40 °C)
- Storage Temperature: 23–111 °F (-5–45 °C)
- Built-in charge controller
- Built-in low battery protection
The Nature's Generator Power Pod also includes a compartment on the top section of the product. The fuse connector for expansion purposes is stored here. You can also store any other items inside the compartment that you may want to keep handy with your unit.

Nature's Generator Power Panel
- 100 Watt panel
- Cell Type: Monocrystalline
- Voltage: 17 ~22V
- Fuse: 8A
General
- Dimensions: 840 x 670 x 35 mm or 33 x 26.4 x 1.4 inch
- Weight out of box: without cart and cable - 15 lbs
Nature's Generator Power Transfer Kit
- Connects to indoor breaker panel
- Use during power loss or as main source of power transfer
General
- Product dimensions - Power Transfer Switch: 8 x 4.75 x 13.25 in.
- Weight out of box: Power Transfer Switch - 12 lbs
- Operating temperature: 32-104 °F (0-40 °C)
- Storage temperature: 23–111 °F (-5–45 °C)
- Warranty: 12 Months
What Can You Get
Nature's Generator
- 1 × 1800W Nature's Generator
- 1 × Accessory Box (Heavy Duty Cart)
- 1 × Smart Key
- 1 × User Guide
- 1 x Power Cord (Inside back compartment)
- 12 months Warranty
Nature's Generator Power Pod
- 1 x Nature's Generator Power Pod
- 1 × User Guide
- Hardware box
- 12 months Warranty
Nature's Generator Power Panel
- 3 x 100W Monocrystalline Solar Panel
- 3 × Accessory Box (Stand and Wheels)*
- 1 x MC4 Branch Connector
- 2 x 50ft Solar Panel Cable
- 12 months Warranty
*Stand and Wheels kit will be provided for free upon request. Some assembly required.
Nature's Generator Power Transfer Kit
- 1 x Power Transfer Kit
- 1 x Conduit for Power Transfer Kit
- 1 x Cable clamps for Power Transfer Kit
- 10 Foot 12AWG Power cord for Power Transfer Kit
- 12 months Warranty
View and Download
Run Times with Nature's Generator + Power Pod
- Smartphones - 100+ Recharges
- Tablets - 60+ Recharges
- Laptops - 40+ Recharges
- LED Light Bulbs - 100+ Hours
- Point of View Camera - 300+ Recharges
- Mini Fridge - 15-20 Hours
- Refrigerator - 12-20 Hours
- 32" LED TV - 30+ Hours
- Oscillating Fan - 30+ Hours
- CPAP Machine - 20+ Hours
- Circular Saw - 5 Hours of Normal Use
- Corded Drill - 9 Hours of Normal Use
Order a Nature's Generator Platinum PE System 1800W + 3x 100W Solar Panel + 1x Power Pod + 1x Power Transfer Solar Generator Kit today from SolarParadise.com. Free shipping + free gifts on all of our Nature's Solar Generators. Buy today and get a discount, free shipping, and a free gift!
Financing
Available
Clear, transparent terms. Fair rates.
No prepayment penalties.
Pay Over Time
Through Bread Pay™, we offer easy and affordable financing options so you can pay for your purchase over time.
Affordable Monthly Plans
Buy now and pay for your purchase over time at competitive interest rates.
No Prepayment Penalties
Pay for your purchase with monthly payments and prepay at any time without penalty.
Easy Application
Get a decision in seconds with no obligation to buy. Checking your rate won't affect your credit score. Your data is safe and encrypted.
![]() |
Please allow 4-7 business days for your order to arrive. |
|
![]() |
Returns are easy, simply contact us for a returns number and send your item to our returns center for fast processing. We'll get you a replacement or refund in a snap! |
At Solar Paradise, we are dedicated to providing high-quality solar solutions to help you harness the power of the sun for a sustainable future. Here are some reasons why you should choose us as your trusted solar partner:
Expertise and Knowledge
Our team of experts has extensive knowledge and experience in the solar industry. We stay up-to-date with the latest technology and trends to offer you the best products and solutions for your solar needs. We will work with you to design a customized solar system that meets your unique requirements and budget.
Top-Quality Products
We source our products from reputable manufacturers who share our commitment to quality and sustainability. Our solar panels, inverters, and batteries are all tested and certified to ensure they meet our high standards for performance and reliability. We offer a wide range of products to suit your needs, from small portable solar generators to large-scale commercial installations.
Excellent Customer Service
At Solar Paradise, we prioritize customer satisfaction above all else. Our friendly and knowledgeable team is always available to answer your questions and provide guidance throughout the solar installation process. We will work closely with you to ensure that you are completely satisfied with your solar system and that it meets your expectations.
Competitive Pricing
We understand that solar can be a significant investment, which is why we offer competitive pricing on all of our products and services. We believe that solar should be accessible to everyone, and we work hard to keep our prices affordable without compromising on quality.
Environmental Responsibility
We are passionate about protecting the environment and reducing our carbon footprint. We believe that solar is one of the most effective ways to do this, which is why we are committed to promoting solar energy and making it accessible to everyone. When you choose Solar Paradise, you are choosing a company that shares your values and is dedicated to creating a sustainable future for generations to come.
In conclusion, at Solar Paradise, we pride ourselves on our expertise, top-quality products, excellent customer service, competitive pricing, and environmental responsibility. We are committed to providing you with the best solar solutions to help you power your life with clean, sustainable energy. Choose us as your trusted solar partner and let us help you embrace a brighter, more sustainable future.
Our goal is to consistently provide the best pricing in the marketplace online and we work very diligently to do so. If you happen to see another online shop that offers a lower price than us within six months of your date please let us know and we’ll be happy to refund the difference on your original payment method. Moreover, because we are consistently working with our suppliers to get better rates we know that you can feel very comfortable and confident that you are seeing the best prices that can be provided for the products listed on our site. Moving forward if you find the same item that we carry on another website that has a lower price please submit that to us within six months of your purchase date and we will refund you the difference.
If it is a case of seeing a lower price on another website and we need to send a partial refund simply email us the link to the exact product and brand from our site and also the link from our competitors site so we can inspect the pricing. Again this needs to be within six months from the date of your order and we will review your submission and apply a credit if necessary.
Our 100% Shoppers Best Price Guarantee has some limitations:
-
The item must have already been purchased from our site prior to asking for this to be reviewed and submitted.
-
This does not include rebate programs or specific retailer programs such as buy three get one free type offers or any combination such as that are not eligible
-
The item will need to be in stock from the competitors site that you’re submitting the information from
-
The competitor must be an online store, they may not have a retail location (warehouse, showroom, or physical location)
-
The price match only applies to checkouts directly on this site.
-
The website cannot be a wholesaler, liquidator, distributor, or auction website. Examples are eBay, Liquadation.com, Via Trading, overstock, etc.
-
The competitor must also be someone who has been authorized by the supplier and/or manufacturer to resell the product you are inquiring about
-
The Shoppers Best Price Policy must also include the product listing price and the shipping total, but will exclude any sales tax that gets added at the final purchasing invoice.
Description
Nature's Generator Platinum PE System 1800W + 3x 100W Solar Panel + 1x Power Pod + 1x Power Transfer Solar Generator Kit

Our Nature's Generator Platinum-PE System brings together our Nature's Generator Platinum System and the Power Transfer Kit.
The Nature's Generator Platinum System is a system that allows you to generate and store extended power. With the addition of the Power Transfer Kit you'll be able to link the existing power circuits in your indoor breaker panel to your Nature's Generator Platinum System. You'll have the ability to continue providing power to your most needed items without having to disconnect them from their current outlets.
The Nature's Generator Platinum System provides a combined 1,920W hours of run time and with the included three 100W Nature's Power Panels you can continually use and recharge your system.
*Some assembly required for Power Panels.
Nature's Generator Platinum System PE Highlights
- Extend your run time and energy storage capacity with a combined 1,920Wh of run time by daisy-chaining the Nature's Generator Power Pod to the Nature's Generator.
- Continually recharge the Nature's Generator and Power Pod while in use, using the included Nature's Generator Power Panels.
- The Nature's Generator Power Transfer Kit can be installed next to almost any indoor breaker panel. By connecting your Nature's Generator to the Power Transfer Kit you'll more easily be able to continue providing power to your most needed items in case of power loss.
Get To Know Your Nature's Generator
Front Panel Ports
- 3 x 120-Volt AC outlet (1800 watt max)
- 2 x USB port(UP TO 3A Combined power)
- 1 x 12-Volt DC outlet
- 1 x 300-Watt Wind input
- 1 x 200-Watt Solar input
- 1 x 90-Watt Wall Charging input
Other Port At The Back
- Expansion Port: 175A Anderson Power Pole
- Expansion Port Fuse: 200A
LCD Display: LCD display shows the information of the system. LCD Display Button: Press it to light up LCD display for 30 seconds.
Get To Know Your Nature's Generator Power Pod
Front Panel
- One 12V DC port (240W max)
- Solar Input (200W Max)
- LED multi-color battery fuel gauge
- Expansion Cord to connect to a Nature's Generator or Power Pod - 45in. Long
- Type: AGM Sealed Lead Acid
- Capacity: 100Ah (1,200Wh)
- Built-in charge controller
- Built-in low battery protection
- Expansion port: Anderson Power Pole
Keep plugged in or recharge every 2-3 months of non-use
The Nature's Generator Power Pod also includes a compartment on the top section of the product. The fuse connector for expansion purposes is stored here. You can also store any other items inside the compartment that you may want to keep handy with your unit.
Get To Know Your Nature's Generator Solar Panel
- Rated 100-watts power panel
- Daisy-Chainable to another solar panel using MC4 branch connector
- Includes multiple positions (summer/winter) for optimum sun exposure
- Reinforced with 3.2mm safety, anti-reflective glass
- Included cable management system and wheels for mobility
- Heavy duty anodized durable aluminum frame
- Includes eye bolts for securing the power panel to different surfaces
*Stand and Wheels kit will be provided for free upon request. Some assembly required.
Get To Know Your Nature's Generator Power Transfer Kit
As the Power Transfer Kit links Nature's Generator to the existing power lines in your indoor breaker panel, you can continue providing power without having to move big items like your refrigerator or getting into tight corners to unplug devices from your wall.
How to Use
- Fit the female connector of the included power cord into the power inlet of your Power Transfer Switch.
- Insert the male plug into any of the AC outlets on the Nature's Generator.
Common Circuits to Keep Backed Up
- Lights
- Garage Doors
- Refrigerators/Freezers
- Common areas
*Important: Installation of the Power Transfer Kit must be performed by a qualified electrician in compliance with all applicable electrical codes. Do not charge Nature's Generator by wall through AC input port when using Power Transfer Kit.
Specifications
- SKU: HKNGPTPE
Nature's Generator
Inverter
- Output Power: 1800 watt max / 1440 watt continuous /2880 watt peak
- Pure sine wave
- Output voltage: 120V
- Output frequency: 60Hz
Battery
- Type: AGM Sealed Lead Acid
- Capacity: 12V 60Ah (720Wh)
- Keep plugged in or recharge every 4 months of non-use
- Built-in charge controller
- Built-in low battery protection
Ports
- USB Port: 5V, up to 3A (15W)
- 12V DC Port: up to 20A (240W max)
- Expansion Port: 200A fuse
Chargers
- AC Charger: 90W
- AC Charger Indicator: red (charging) and green (charged)
- Solar Charger: 200watt
- Wind Charger: 300watt
General
- 18 x 12 x 15 in (47 x 30 x 38 cm) without cart
- 23 × 17 × 22 in ( 57 × 42 × 55 cm) with cart
- Operating temperature: 32-104 °F (0-40 °C)
- Storage Temperature: 23–111 °F (-5–45 °C)
- Weight: 83 lbs (37.6 kg)
Nature's Generator Power Pod
- Type: AGM Sealed Lead Acid
- Capacity: 100Ah (1,200Wh)
- One 12V DC port (240W max)
- Solar Input (200W Max)
- LED multi-color battery fuel guage
- Expansion Cord to connect to a Nature's Generator or Power Pod - 35in. Long
- Keep plugged in or recharge every 4 months of non-use
General
- Power Pod Dimension: 18 x 12 x 15 in.
- Weight out of box: 92 lbs
- Operating temperature: 32-104 °F (0-40 °C)
- Storage Temperature: 23–111 °F (-5–45 °C)
- Built-in charge controller
- Built-in low battery protection
The Nature's Generator Power Pod also includes a compartment on the top section of the product. The fuse connector for expansion purposes is stored here. You can also store any other items inside the compartment that you may want to keep handy with your unit.

Nature's Generator Power Panel
- 100 Watt panel
- Cell Type: Monocrystalline
- Voltage: 17 ~22V
- Fuse: 8A
General
- Dimensions: 840 x 670 x 35 mm or 33 x 26.4 x 1.4 inch
- Weight out of box: without cart and cable - 15 lbs
Nature's Generator Power Transfer Kit
- Connects to indoor breaker panel
- Use during power loss or as main source of power transfer
General
- Product dimensions - Power Transfer Switch: 8 x 4.75 x 13.25 in.
- Weight out of box: Power Transfer Switch - 12 lbs
- Operating temperature: 32-104 °F (0-40 °C)
- Storage temperature: 23–111 °F (-5–45 °C)
- Warranty: 12 Months
What Can You Get
Nature's Generator
- 1 × 1800W Nature's Generator
- 1 × Accessory Box (Heavy Duty Cart)
- 1 × Smart Key
- 1 × User Guide
- 1 x Power Cord (Inside back compartment)
- 12 months Warranty
Nature's Generator Power Pod
- 1 x Nature's Generator Power Pod
- 1 × User Guide
- Hardware box
- 12 months Warranty
Nature's Generator Power Panel
- 3 x 100W Monocrystalline Solar Panel
- 3 × Accessory Box (Stand and Wheels)*
- 1 x MC4 Branch Connector
- 2 x 50ft Solar Panel Cable
- 12 months Warranty
*Stand and Wheels kit will be provided for free upon request. Some assembly required.
Nature's Generator Power Transfer Kit
- 1 x Power Transfer Kit
- 1 x Conduit for Power Transfer Kit
- 1 x Cable clamps for Power Transfer Kit
- 10 Foot 12AWG Power cord for Power Transfer Kit
- 12 months Warranty
View and Download
Run Times with Nature's Generator + Power Pod
- Smartphones - 100+ Recharges
- Tablets - 60+ Recharges
- Laptops - 40+ Recharges
- LED Light Bulbs - 100+ Hours
- Point of View Camera - 300+ Recharges
- Mini Fridge - 15-20 Hours
- Refrigerator - 12-20 Hours
- 32" LED TV - 30+ Hours
- Oscillating Fan - 30+ Hours
- CPAP Machine - 20+ Hours
- Circular Saw - 5 Hours of Normal Use
- Corded Drill - 9 Hours of Normal Use
Order a Nature's Generator Platinum PE System 1800W + 3x 100W Solar Panel + 1x Power Pod + 1x Power Transfer Solar Generator Kit today from SolarParadise.com. Free shipping + free gifts on all of our Nature's Solar Generators. Buy today and get a discount, free shipping, and a free gift!
Financing
Financing
Available
Clear, transparent terms. Fair rates.
No prepayment penalties.
Pay Over Time
Through Bread Pay™, we offer easy and affordable financing options so you can pay for your purchase over time.
Affordable Monthly Plans
Buy now and pay for your purchase over time at competitive interest rates.
No Prepayment Penalties
Pay for your purchase with monthly payments and prepay at any time without penalty.
Easy Application
Get a decision in seconds with no obligation to buy. Checking your rate won't affect your credit score. Your data is safe and encrypted.
Delivery And Returns
![]() |
Please allow 4-7 business days for your order to arrive. |
|
![]() |
Returns are easy, simply contact us for a returns number and send your item to our returns center for fast processing. We'll get you a replacement or refund in a snap! |
Why Buy From Us
At Solar Paradise, we are dedicated to providing high-quality solar solutions to help you harness the power of the sun for a sustainable future. Here are some reasons why you should choose us as your trusted solar partner:
Expertise and Knowledge
Our team of experts has extensive knowledge and experience in the solar industry. We stay up-to-date with the latest technology and trends to offer you the best products and solutions for your solar needs. We will work with you to design a customized solar system that meets your unique requirements and budget.
Top-Quality Products
We source our products from reputable manufacturers who share our commitment to quality and sustainability. Our solar panels, inverters, and batteries are all tested and certified to ensure they meet our high standards for performance and reliability. We offer a wide range of products to suit your needs, from small portable solar generators to large-scale commercial installations.
Excellent Customer Service
At Solar Paradise, we prioritize customer satisfaction above all else. Our friendly and knowledgeable team is always available to answer your questions and provide guidance throughout the solar installation process. We will work closely with you to ensure that you are completely satisfied with your solar system and that it meets your expectations.
Competitive Pricing
We understand that solar can be a significant investment, which is why we offer competitive pricing on all of our products and services. We believe that solar should be accessible to everyone, and we work hard to keep our prices affordable without compromising on quality.
Environmental Responsibility
We are passionate about protecting the environment and reducing our carbon footprint. We believe that solar is one of the most effective ways to do this, which is why we are committed to promoting solar energy and making it accessible to everyone. When you choose Solar Paradise, you are choosing a company that shares your values and is dedicated to creating a sustainable future for generations to come.
In conclusion, at Solar Paradise, we pride ourselves on our expertise, top-quality products, excellent customer service, competitive pricing, and environmental responsibility. We are committed to providing you with the best solar solutions to help you power your life with clean, sustainable energy. Choose us as your trusted solar partner and let us help you embrace a brighter, more sustainable future.
100% Best Price Policy
Our goal is to consistently provide the best pricing in the marketplace online and we work very diligently to do so. If you happen to see another online shop that offers a lower price than us within six months of your date please let us know and we’ll be happy to refund the difference on your original payment method. Moreover, because we are consistently working with our suppliers to get better rates we know that you can feel very comfortable and confident that you are seeing the best prices that can be provided for the products listed on our site. Moving forward if you find the same item that we carry on another website that has a lower price please submit that to us within six months of your purchase date and we will refund you the difference.
If it is a case of seeing a lower price on another website and we need to send a partial refund simply email us the link to the exact product and brand from our site and also the link from our competitors site so we can inspect the pricing. Again this needs to be within six months from the date of your order and we will review your submission and apply a credit if necessary.
Our 100% Shoppers Best Price Guarantee has some limitations:
-
The item must have already been purchased from our site prior to asking for this to be reviewed and submitted.
-
This does not include rebate programs or specific retailer programs such as buy three get one free type offers or any combination such as that are not eligible
-
The item will need to be in stock from the competitors site that you’re submitting the information from
-
The competitor must be an online store, they may not have a retail location (warehouse, showroom, or physical location)
-
The price match only applies to checkouts directly on this site.
-
The website cannot be a wholesaler, liquidator, distributor, or auction website. Examples are eBay, Liquadation.com, Via Trading, overstock, etc.
-
The competitor must also be someone who has been authorized by the supplier and/or manufacturer to resell the product you are inquiring about
-
The Shoppers Best Price Policy must also include the product listing price and the shipping total, but will exclude any sales tax that gets added at the final purchasing invoice.

Choose Your Battery Bank Capacity | Solar Kit Size

Choose Your Battery Bank Capacity | Solar Kit Size

Choose Your Battery Bank Capacity | Solar Kit Size

Choose Your Battery Bank Capacity | Solar Kit Size

Choose Your Battery Bank Capacity | Solar Kit Size

Choose Your Battery Bank Capacity | Solar Kit Size

Choose Your Battery Bank Capacity | Solar Kit Size

Choose Your Battery Bank Capacity | Solar Kit Size

Choose Your Battery Bank Capacity | Solar Kit Size