BIRUGEAR Black USB Home Wall Travel AC Charger Power Adapter for BLU Vivo Air Input: 100V - 240V (U.S. & World Standard) Intelligent IC chip inside recognizes a fully charged battery and automatically switches to a saver mode to prevent overcharging and short circuit. LED light power indicator. You must have a USB charging cable (sold separately) in order to charge your MP3 player with this charger. Best replacement for original MP3 player travel charger.