The ChargeBlock case for iPhone 4 is a lightweight, full-length case with the convenience of a built in extra battery for peace of mind. You no longer have to worry about your iPhone running out of power or finding a place to recharge. The ChargeBlock case is the perfect iPhone accessory with its comfortable, non-slip grip and slim figure (less than 3 oz.). The battery has enough power to completely charge a depleted iPhone 4 with juice to spare. The ChargeBlock case also has a micro USB connection that allows for charging and syncing with iTunes.