Maxboost iPhone 4S Battery Case/iPhone 4 Battery Case (1900mAH, Fits all versions of Apple iPhone 4 & 4S) - Detachable Battery Charger Case External Rechargeable Battery Pack Charging Power Case The powerful 1900mAh built-in battery can effectively double the battery life of iPhone 4/4S, which adds additional 8 hours of talk time and 10 hours of web browsing time. Featuring an innovative detachable design, one can easily detach the battery from the fusion case, and enjoy the joy of ultra slim protection. The case featuring a MicroUSB input port and an Apple 30pin output port. It can be charged together with the iPhone via included the MicroUSB cable. The extended batteries come in black and white, while the slim cases have 8 different colors. 16 stylish color combinations to choose from. The case also has the following functions built-in: charging switch, LED battery level indicator, charge & sync through the case, function button cutouts.