This iPhone®3G(S) case with built-in battery offers protection and power at the same time. Super compact and lightweight, it shields the phone while extending your talk time.
Energizer AP1000 Iphone 3G Battery Case Hard Case Battery for Iphone 3G & 3GS Lithium Polymer Battery, 1000 mAH @ 5V, Input: 5V, Max 500 mA Output: 5V, Max 500mA Size: L11.9 x W6.6, x H2.0cm, 0.082kg