The Fenix ARB-L18-2600 is a high capacity 18650 Li-ion rechargeable with a protection circuit in the anode to help prevent short circuits, over charge/discharge and over heating. The battery also includes pressure relief vents which expel waste gas in the rare case of an internal short circuit preventing an explosion. Features: - Rechargeable Battery - 2600mAh high capacity - Protection circuitry to prevent short circuits - Pressure vents to prevent explosions - 500 charge cycles - Voltage: 3.6V