battery case for iphone 3G, case for iphone,protectional case for iphone 3G,Leather Case for iPhone 3GS, battery case for iphone 3G, case for iphone,protectional case for iphone 3G,Leather Case for iPhone 3GS TECHNICAL DATA1. Input Voltage: DC4.5V-5.5V2. Input Capacity: 1A3. ... without holding in hands.6.With the built-in high-power, high-quality tone speaker which can amplify the output voice and ...