The TrustFire protected 10440 Lithium battery is equipped with a protection circuit board (PCB) on the negative pole. The PCB can protect the battery from overcharge over-discharging overload and short circuit which can make the battery safer and longer lifespan. The battery is environment friendly and perfect for super bright flash and other devices. - With integrated PCB Protection - Over current protection current: 4A - Over current protection voltage: 0.2V - Over charging protection voltage: 4.25V +/- 25mV - Over discharging protection voltage: 2.5V +/- 50mV - Lithium Ion 10440 cylindrical rechargeable batteries - Lighting or other device needing 3.7V power - Product print '600mAh' the exact capacity is 350mAh