Compatible with any 510 Standard USB charging port, the Ego Winder Charger is an extremely convenient power source. Charge your battery by screwing it into the device and plugging the other end into a USB power source. The LED light on a battery will flash 3 times then turn solid in color; the light on the USB charger will be red when charging. Once fully charged, the USB charger will display a solid green light, and the battery’s LED light will turn off. The USB charger can be plugged into most USB ports, and is also usable with a USB wall adapter (sold separately).Chargers are sold individually.