1.High-strength die-casting alloy,safe and durable; 2.Decoration shell made of stainless steel,copper,and aluminium plate; 3.Special antioxidant shim; 4.Suitable for toughened glass door with thickness of 10 to 12 centimeter(or manufacturing according to the thickness of the glass); Upper clamping head of various specifications are available and can be used in conjunction with spring from DORMA,GEZE,NEWSTAR,BONGO,CROWN and etc.