Article No. GYL-2.50A Solar Panel: 2.5W a-Si Silicon Solar Panel Storage Battery: 3.7V2800mAH Rechargeable Li-ion Battery. Controller: Built-in Controller Inside the Lamp. Appliance: Portable LED Lamp with less than 24 LED. Working time: 5hrs/day. Protection: Over-charging, Reverse Charging, and Over-discharging Protection. Components: A-Si Panel, 1 piece: LED Lantern or LED Bulb, 1 Piece; User's Manual, 1 Piece. Features: 1. Low Cost, around USD10/pc. 2. Long Service Life. 3. Low Maintenance Expense: at most 1 dollar per year. 4. High brightness: brighter than 10 candles. 5. Convenient: the lamp can be removed from the system and used in the places you hope to use.