The UtraFire protected 18650 rechargeable cell 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. - Protected against over-charging and over-draining - Operating voltage: 3.70 - 3.80V - Capacity: 2400mAh - Maximum charge/drain rate: 1.5C - Overcharging protection point: 4.2V - Overdraining protection point: 2.75V ** Actual product bares "Ultrafire/Protector 2400mAh protected" markings. This image is taken from a sample battery. I'll update the picture shortly to the Ultrafire logo'd one.