List Price: .99 Deal Price: .99 You Save: .00 (79%)The Accessory Power Go Groove ENER-G more than doubles the battery life for your iPhone. Well-designed, sleek, and easy to use, the ENER-G slides onto the back of your phone with a comfort fit design. An ideal power solution for recreation or business activities. 2400mAh battery pack charges through USB cable or iPhone power adapters. Compatible with iPhone 3G and iPhone 3GS.Expires Dec 6, 2010