ARB-L21-4000P is the latest Fenix 21700 Li-ion power battery, featuring sufficient power and steady performance. With an 18A maximum output current and 10A continuous output current, the power of the 21700 battery is twice as powerful as the common 18650/2300mAh battery, which provides the lighting tools with sufficient power and longer duration. The multiple protection ensures the use safety and good performance of the battery; steel shell riveting technology protects the battery against damage; pressure relief vents rapidly expel internal gas.