This External Power Battery Pack and integrated case for iPhone 4G and 4S is an ideal and powerful companion for your iPhone. It acts both as a protective case and also as an excellent external battery pack. The powerful built-in 2500 mAh Lithium-ion Polymer battery can be engaged using the On/Off switch button at your will and it is able to provide additional talk time by up to 6~7 hours for your iPhone4/4S and additional standby up to 5 days. This case is stylish and portable with textured Black non-slip finish: 2 in 1 battery & Docking as well as provides full body coverage for your iPhone4.