SANOXY UltraPower 1900 mAh BLACK Backup Battery Charger for iPhone 4/4S, 4G, 3GS, iPod, iTouch-EXTERNAL, PORTABLE, RECHARGEABLE BATTERY PACK (BLACK) SANOXY 1900mAh External Backup battery for iphone IPod Suitable for iPhone 4/4s/iPod, BLACKBERRY, Samsung , Mobile phone and MP3, MP4 etc Digital Devices. Charge method: Can be charged via USB port of working PC and laptop or via AC adacpter. Weighs only 2 oz-Wireless, Plug Directly To Phone Portable SANOXY for iPhone BATTERY BOOSTER into the input port of the phone and you get a rapid total recharge. WIRE FREE. The charger attaches directly to the phone