Features: Solar Panel: Used to charge mobile phone, MP3, or other USB-charged device. Double USB female port, easily charge device via USB charging cable. You can place the panel in the sun and use it to directly charge your device. Perfect for outdoor cycling, climbing, hiking, camping, traveling, etc. Solar Controller: Build-in industrial micro controller. Fully 4-stage PWM charge management. One-key setting, digital display, auto memory function. Dual mosfet reverse current protections, low heat productions. Build-in short-circuit protections, open-circuit protections, reverse protections, over-load protections.