WindFire 2X 18650 3.7V 4000mAh Lithium Rechargeable Batteries + 18650 Lithium Battery Charger (110V~240V AC) Combo WindFire rechargeable 18650 batteries travelling charger for 18650 batteries, with standard US plug High capacity: 4000mAh 18650 rechargeable battery Voltage: 3.7V, Can be charged over 500 times The battery can be used on many LED flashlight, laser devices and other electronic products