I phone 4/4s cover with external rechargeable battery must have accessories if you have a iphone 4 or 4s great phones but battery isnt the best on them with this cover you never have to worry about your battery i have one on my own iphone 4s and ive sold all my friends them that have iphones cant recommend them enough ill put up pictures and a video so you can see how they work,
for any more information get in contact
Thanks.