External Charger Batttery Pack for iPhone 4/4S. iL4 Power Battery Plate White, Make your iPhone's life longer!!! Its back is made of the tempered glass, fits the iPhone 4/4S body naturally, and does not affect the original design style of iPhone 4/4S!! The thinest and smartest battery! It looks like just iPhone!! Can be charged through specified dock connector, and achieves synchronization with the iTunes. Increase the life of iPhone 4/4S by about 1 time and only one action can simply install or remove it. With function of automatic shutdown after charging, it automatically stops charging.