TRIM™ is the epitome of form meeting function perfectly. With TRIM™ we have utilized a special technique that fuses together a semi-soft frame with an ultra tough polycarbonate back panel. This not only provides a great structure for protection, but also offers superb grip to battle those butter fingers. The distinctive grooves that travel around the edge of the unit offer substantial shock protection from accidental drops, and also make it effortless to get a firm grip when it rests in your hand. In addition TRIM™'s semi transparent tinted back provides a great way to show off all the natural goodness of the iPhone 4's design.