Juice Pack Plus for iPhone 4 & 4s by MophieMore than Doubles Battery Life!2000 mAh capacity, advanced battery technology delivers an incredible amount of ?juice? in a small form factor, more than doubling battery life.Standby/Charging Switch Features a simple toggle switch which allows for standby and charging mode so you only have to use the juice pack plus battery when you need it.MFi ApprovedCertified and approved by Apple for safe & secure charge on your iPhoneCharge and SyncCharge and sync your iPhone to iTunes without removing it from the juice pack plus by using the included USB cable.Protective Rubberized BandThe juice pack plus provides a comfortable ergonomic design with the complete protection of a dual-injected hard shell case with protective shock-proof rubberized band.Status IndicatorThe 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.Acoustic Sound EnhancementThe 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.