iPhone 4 backup case

Features:

With changeable bumpers
Super slim design
Easy to use, plug and play, Auto sleep.
With on/off button and LED power level indicators.
Able to charge and sync at the same time.
Over voltage protection, over current protection, over charging protection, short-circle protection, thermal protection
Apple Made-for-iPhone approval
A-grade battery cell, Seiko chipset inside

Specifications:

Capacity:1500mAh (Li-polymer battery cell)
Weight:60g
Input:5V 500mA, Output: 5V 1A max
Size:126*62*14.5mm