Amzer Silicone-Perforated PolyCarbonate Hybrid Case for iPhone 4 - 1 Pack  Black/Blue This case is made up of a hybrid of the contemporary Silicone skin case and the classic Polycarbonate hard case. The first layer, Silicone, protects your entire iPhone. The second layer, a Perforated Polycarbonate hard shell, protects the back of your device. The smooth outer back shell provides sure grip to keep your device from dropped or bumped. Quality material used for this hybrid case provides shield and avoid scratches. Double layer protection without adding bulk on your device.