iPhone 4 Battery Case: Extended Back up Power Bank External Protective Charger Pack for Iphone 4S / 4 Lightning Fast Charging Port Station, Slim Fit Slider Design, Full Body Protection, On/off Switch, LED Bat

This ultra powerful, built-in battery can effectively provide more than 120% of additional battery life to your iPhone 4/4S. That's more than 12 hours of talk time and 15 hours of web browsing time!
Featuring a 100% guaranteed, protective rock hard shell with a smooth rubber finish, and access to all phone ports. High end protection that does not compromise the slim look and feel of your iPhone 4/4S.
Simultaneously charge the phone and battery pack via the micro USB included. A slick LED light indicator on the bottom of the case shows you the charger battery power level. Control the use of your reserve battery power with the flick of a switch!
This charger case has full compatibility with ALL versions of iOS. All this and you add only mm's of extra thickness to your existing iPhone. This is among the slimmest cases available.
Offering the fastest charge time and true, measured power capacity available on the market - as compared against similarly priced charger cases. Less than 2 hours to charge your iPhone from zero power. What you get is the powerful 2 in 1 combination of a fully protective case AND an external battery source for your iPhone 4/4S!