This Juice Pack Plus™ more than doubles the battery life of your iPhone 4 with its built-n 2000mAh rechargeable battery. The comfortable dual-injected design gives your iPhone 4 the complete protection of a hard shell case with a shock-resistant rubberized band. The rechargeable lithium polymer battery virtually doubles your time to rock, talk, surf and send. Charge and sync your iPhone to iTunes without removing it from the case by using the included USB cable. The case design acts as a virtual speaker box, redirecting sound from the bottom of the iPhone 4 to the front, resulting in a richer, fuller sound quality. It features a simple toggle switch that allows for standby and charging mode so you only have to use the Juice Pack Plus™ battery when you need it. The integrated LED status indicator on the bottom tells you exactly how much juice is left at the push of a button. It also indicates the charging status so you know before you go.