The result of this market development are phones with very smooth surfaces, both in piano lacquer design or, as in the Nokia Asha 303 consisting of anodized aluminum (battery cover) and smooth, painted plastic (housing body). These are the best conditions to ensure that the inclined users times just slips be expensive erstandenes device out of his hand and makes an involuntary drop test.
Gone are the times when there were on the phones side non-slip, knurled or rubber / dull lacquered grip zones, namely in the factory. Now you have to be such a slip protection to buy later. The price of 3.90 euros (April 2012) is small in relation to the price of the phone, but the need is still annoying. The fact that it is a shell, the phone still around "thicker" and highlights the efforts of manufacturers to produce increasingly compact devices, again a little way on.
The sheath is made of thermoplastic polyurethane (TPU) and not, as the product name contradictory also mentioned, made of silicone. Silicone sleeves bring a material contingent feeling of stickiness with it. This often hinders the speedy removal from pocket or breast pocket when the phone rings. The TPU used in this unpleasant effect does not exist. The lateral structuring the surfaces in the grip area of the desired slip protection is very good at the same time ensuring faultless operation of the sides of the unit keys. The shell sits a perfect fit. Pleasant was also a selection of other colors than black, but that may perhaps still to come.