This Fenix USB Rechargeable battery is a high capacity 18650 Li-ion USB rechargeable battery with a built-in micro-USB charging port. It also includes a protection circuit in the anode to help prevent short circuits, over charge/discharge and over heating. These USB rechargeable batteries can quickly be charged without the need for a separate charger. This not only saves you money from purchasing a charger, but also provides the convenience of not having to carry around another device. This will work in all of the current models that utilize a li-ion 18650 battery. A micro-USB charging cord is NOT included. FeaturesMicro-USB charging port3500mAh high capacityUSB rechargeable batteriesProtection circuitry to prevent short circuitsPressure vents to prevent explosions500 charge cyclesVoltage: 3.6VCharging Current: Recommended 1A, maximum 2ACharging Current USB Port: 0.8AWeight: 1.8 ounces (50.2g)Size: Length: 2.8"(70mm) Diameter: 0.7"(18.6mm)Warranty Period: 12 month from date of purch...