Light-weight, super-slim design to carry with your iPhone or iPod Conveniently charged via any USB ports High-capacity, rechargeable lithium-ion battery LED indicator for battery power level This item can be used as an emergency battery anytime you dont have access to a computer, car charger or wall charger. When you need to recharge the backup battery just use the iPod/iPhone USB sync cable to connect it to computers USB port or USB AC charger. Note: You can not charge the phone and the battery at the same time.
NOTE for iPod users: the battery pack blocks the headphone jack while in use. you can not use this battery pack and the iPod simultaneously, due to the orientation of the headphone jack. this is not an issue with the iPhone, which has the headphone jack on the top.