External Power Bank for iPhone 4/4S Portable Phone Charging Case Extended Backup Battery Charger(2300MAH,Red) Extended power pack for your iPhone ,available charging when walking ,having class,on work,on the subway,in car.Anywhere at anytime! Easy using,slide your iphone 4/4S to the bottom and turn it ON when charging Be convenient,you can just keep it in hand .Easy carrying with and offer extra full protect to your iPhone Extend standby time up to 210 hrs for iPhone 4/4s;talk time up to 8hrs;Audio playback 28hrs Capacity:2000mAh;Size:13*6.5*2 cm; Weight:75g;Material quality :general-purpose plastics ;Build in battery:Grade A lithium battery