Rikki Knight&trade; Keep Calm and Grow a Mustache Lime Green Color Design iPhone 4 & 4s Case Cover (White Rubber with bumper protection) for Apple iPhone 4 & 4s Protects your Phone without adding a lot of bulk. Use rechargeable lithium polymer battery. Integrated power switch allows you to switch on/off the battery case. Only use the battery when you need it. We can provide custom phone cases with any design for you. If you want, please contact us! Offer the Easiest Way to Install and Remove.