Structure and manufacturing process * Porcelain Core: manufactured with high alumina porcelain raw materials; * Silicone Rubber Sheds: HTV silicone rubber, with alternative shed profile； * With the high pressure injection molding at high temperature, the silicone housing is fully bonded to the porcelain solid core which cemented fitting in advance. The silicone housing adheres directly to the fitting without the need for artificial sealing; Feature * High mechanical strength with much lower of deflection * Excellent performance of anti-pollution; * Long lifetime is guaranteed; * Maintenance expenditure is reduced to a minimum;