WindFire 2X 18650 4000mAh 3.7V Rechargeable Li-Ion Battery + 18650 battey charger Combo For LED Flashlight Torch LED Headlamp Bike Bicycle Light WindFire rechargeable 18650 batteries travelling charger for 18650 batteries, with standard US plug High capacity: true 4000mAh 18650 rechargeable battery Voltage: 3.7V The battery can be used on many LED flashlight, laser devices and other electronic products