Specifications:

Lithium-ion Battery Case for iPhone 4 1850mAh... Get on-the-go power and protection for your iPhone 4 in a sleek light-weight external rechargeable battery case. The Aluratek Lithium-ion battery Case is designed to fully protect and double the time you have to talk web browse listen to music play games watch videos on your iPhone 4! The Battery Case a rechargeable lithium-ion battery disguised inside a low-profile black shiny hardshell case that is form fitting to your iPhone. The Battery Case comes with two attachable frames (clear and black) to give your phone maximum protection while enhancing its look and feel.