The listing, External Power Charger iPhone 4/4S has ended.
This is an external power source for the iPhone 4/4S. You simply charge up the case & use it when your iPhone is dying. There's an off/on switch so you can leave it on your phone all day until you need it. The button on the back by the lines is to tell you how much charge it has. I don't have an android charger anymore so I have no use for it. All you need is an android charger for it. I don't recommend charging the case while you have it on your iPhone though. Great to have in an emergency. I paid well over $35 for it. Ask any questions.