High performance rechargeable battery from Nitecore specially designed for high drain devices like Nitecore TM series and other high power LED search light and tactical flashlights. Features: Nitecore 18650 3.7V Protected Li-ion rechargeable batteries. Protected: Internal PCB protection prevents under-voltage at 2.5V and over-voltage at 4.25V Capacity: 3400mAh Voltage: 3.7V Chemistry: Li-ion Recharge: up to 500 cycles Length: 2.73" / 69.3mm Diameter: 0.74" / 18.7mm Weight: 1.7oz (48.2g)