Features: Semi-flexible: the panel can be flexed to a maximum of 30, ultra-thin: solar panel is only 2.8mm thick, this allows the panel to be flush mounted to curved surfaces like RV's, sailboats, campers, tents, etc.  Highly efficient monocrystalline solar cells.  This product can charge 12V lead-acid batteries, including 12V lithium and other equipments.  The way of the power supply is energy saving and environmental protection.  Suitable foroutdoor working, travelling or camping.   Specification: Maximum Power [Pmax]: 20/30/40/55W+0. 25W;  Working voltage [Vmp]: 18V+0. 3V;  Working Current [Imp]: 1.11A*0. 15A;  Short Circuit Current[Isc]: 1.16A+0. 15A;  Open Circuit Voltage [Voc]: 22V+0. 8V;  Temperature coefficient of the voltage:(0.06510土0.15)%/℃;  Temperature coefficient of current: -(160±10)MA/℃;  The temperature coefficient of power: -(0.5±0.05)%/℃;  Maximum System Voltage: 20V;  Ambient temperature:-40/℃-+85/℃(40°F to185°F);  Air resistance: 50 psi(2400 pascals);  Snow resistance: 113 psi (5400 pascals);  Hail impact: 25mm (1 inch)at 23m/s (52mph);  Item Size: 420 * 280 * 2.8mm;  Net Weight: 410g;  Package Size: 44.5 * 30.5 * 4cm / 17.5 * 12.0 * 1.6oz;  Package Weight: 1194g / 42.1oz;   Package List: 1 * 20W Monocrystalline Solar Panel;  1 * Cable;  1 * Manual