mophie Juice Pack Air Case and 1000 mAh Rechargable Battery for iPod Touch 4th Gen (Blue) The juice pack air is a rechargeable Smart Battery concealed inside of a low-profile, light-weight, soft-touch case. Toggle between Charging and Standby with the flick of a switch. The juice pack air is designed to virtually double the time you have to Rock, Watch, Surf and Send with your 4th gen iPod touch. Charge and sync your iPod touch to iTunes without removing it from the juice pack air by using the included USB cable. The juice pack air for iPod touch incorporates a pass-through design that allows access to all your ports and controls. The juice pack air not only adds battery life, it is a protective form-fitting case with an ultra-thin, light-weight, low-profile design.