a) High quality biodegradable material as the key enviromental friendly design. b)All round use-centred design of improve usability and user experience. c)Scratch,dust and oil proof. d)Combines gripability and comfortable feel. e)Comfortable patterns on the sides to provide great grippabilit. f)Built in protective cover for the headphone jack,dock conector, and speackers. g)Built in protective cover for the camera.