Know you'll need your phone in 20 minutes but it wont make it that long? That's when the PureGear Battery Charger comes in handy. Plug the battery charger into your iPhone 3GS, Verizon, or AT&T iPhone 4 and continue to make business calls or email as you were. The PureGear Battery Charger will extend the battery life of your iPhone or iPod Touch for up to another hour. Included is a USB cable to charge up your PureGear device to have it ready on hand for the next time your phone may run out of juice. this pint sized battery charger can easily be stored in a bag or even your pocket wherever you travel.