MaximalPowr 1200mAh AAA Rechargeable Ni-MH Battery 4pc Pack with "BONUS" - Flexible Clip-on LED Book Reading Light, Black color. AAA Rechargeable Ni-MH Battery: 1. It's to power the flexible clip-on LED book reading light and any other devices that are powered by AAA batteries. Chemistry: Ni-Mh, Output Volts: 1.25V, Capacity: 1200mAh. It works with all Ni-Mh chargers and can be recharged up to 1000 cycles. Special Features of LED Clip-on Reading Light: Ultra-bright LED with options of single and double LED light - Two lighting heads each contains one large LED light and on-and-off switch. No flicker - Each head has a lenses over the LED making the light spreads evenly with no hot spots. Adjustable clamp can grip objects of different thickness with EVA covered in the back of the clip to protect the gripped material. It can clip onto books, kindle, music stand or just about anything else. Lamp post can be adjusted to the required angle and shape to accommodate the full range of lighting needs. It's is low power-consumption for long lasting battery life. It's powered by 3 AAA batteries. Batteries are included.