Power your gear with the FenixA(R) Rechargeable 18650 Battery. This Battery features over-charge protection, over-discharge protection, short-circuit protection, and overheating protection. Plus, pressure vents expel waste gas in the case of an internal short circuit, preventing explosion. ARB-L18-3500 Rechargeable Battery 3500mAh high capacity Protection circuitry to prevent short circuits Pressure vents to prevent explosions 500 charge cycles