... long operation time Product Features:1) High capacity 20000mAh external backup battery for your iPhone 3G,3GS,4G,4GS,iPod, ... short circuit / discharge10) Circle Time:≥500 Times11) LED indication for Battery Status12) Size: 135x70x22 mm13) Color: 2 color for you ... communication will win a long term cooperation! )Photo reference : External Battery Charger 20000mAh USB Power Bank for iPhone/ipad mini