Just hang it on your backpack and the polycrystalline silicon solar panel will effectively convert the sun power to electric energy, so you can charge your phone, tablet and device with a USB port(5V) during camping, backpacking and hiking, which is environmentally friendly and convenient.

• FAST CHARGING: 21W solar panel with more than 18.5% conversion efficiency and the output peak current is 3500mAh totally for the dual USB port
• SMART TECHNOLOGY: Built-in intelligence chip can identify the different devices and change the input current according to your device
• MOST COMPATIBLE: For almost devices like phones, tablets and so on devices with USB ports
• WATERPROOF: PET polymer surface and outer PVC wrap can protect solar panel from unexpected rain or fog, just do not put it in water
• HIGHLY PORTABLE: Hang it on your backpack and make full use of solar energy to charge during trips, and folded it to fit in your backpack for convenient carry

Specification:

• Material: PET solar panel + PVC  
• Conversion efficiency: ≥18.5%
• Power: 21W
• Output voltage: 5V±0.2V
• Output current: 3500mA (peak current)
• Output port: Dual USB 
• Unfold size: 65 * 29cm / 25.5 * 11.4in
• Fold size: 29 * 17cm / 11.4 * 6.6in
• Weight: 697g / 1.5lb