... power case for iphone4/4s with amazing control 2,backup battery accessories 3,portable emergency charger box Power case with Amazing RemoteIt ... is new and innovate accessories for Apple iphone4/4s, external power case box ,backup battery,will be your good partner ... the smartphone is out of power.1) Polymer Lithium Ion Battery core,standard voltage:3.7V2) capacity:2000mAh3) output voltage: ...