Tonez Audio Corp. Battery and Boombox with Rechargeable External Battery, Amplified Speaker and Protective Case for iPhone 4/4S (White) Rechargeable 1800mAh Li-Polymer External Battery & Speaker Case Check charge level, control volume, turn charging feature on/off, turn speaker on/off from front panel Use existing iPhone 4/4S power cords Protective Case, Sleek Design Allows usage while charging, fully recharges phone in 3-5 hours