Sanoxy UltraPower 1900 mAh Backup Battery for iPhone 4/4S, 4G, 3GS, iPod, iTouch, iPhone 4/4S, iPhone 3S, iPod - Retail Packaging - Black 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