that is thermoplastic and non silicone. it is smooth and shiny and not anti-skid as it could have been with a real silicone. the one does not pleasant feel of silicone. damage. therefore it would have been more effective and also more comfortable: this thermoplastic covering the buttons too hard, making especially handling the really hard power button ... damage. otherwise it is properly designed and thickness of the edge of the phone (just 10 mm) still better help hold it in hand, while the bare phone is really a real soap.
