Cell Phone cases are made of a hard plastic with a silicon inner lining.   Each case snaps on.  The printing is heat applied so it will not scratch or rub off.  Compatible devices are as follows: Verizon iPhone 4, iPhone 4, iPhone 3G/3GS, Samsung Galaxy S Vibrant; iPod Touch 4G,iPod Touch 2G, Blackberry Bold 9700,  and Blackberry Curve 8520/9300/3G.