Featuresr high efficiencyr built with 12w sunpower polysilicon solar panels its maximum solar conversion efficiency is up to 22 great for providing power to charge two devices simultaneously while converting extra sunlight into energy and storing in the built in batteryr high capacityr internal 10000 mah lithium polymer battery rechargeable via solar panels is ideal for charging your smartphones tablets gps or other usb enabled devices with 4 led lights to indicate battery levelsr dual