The TrustFire protected 18650 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.   - The voltage of full charge and cut-off discharge is 4.2V and 2.75V  - Don't heat， incinerate or reverse polarity  - Environment friendly<img src="http://112.74.112.28/down/products/415260/415260_000.jpg">