ThinkMax 4-in-1 4 Battery Charger for Hubsan By Thinkmax 4 In 1 X4 Battery Charger For Hubsan X4 WLtoys UDI JXD Syma JJRC RC Quadcopter Voltage input: DC 5V; Voltage output: 4.2V  5%; Current output: 350mAh - 410 mAh Charging 4 battery at one time, Over charge protection, Short circuit protection Not including any batteries