A durable PC & ABS hard plastic case protects your phone from damage and it houses a rechargeable battery that virtually doubles the life of your phone. Concealed inside is a loud, bright high voltage stun gun that produces a painful “sting”.
Yellow Jacket has two safety features that help prevent accidental discharge while being easily deployable in an instant. The external battery can charge your iphone for up to one full extra battery charge.
See more at http://www.yellowjacketcase.com/iphone-4-4s-case.