Zamak 5 chrome provide of automatic return spring thread Ø 2,8 mm.
Interchangeable left or right hand doors.
Pretension 10° to 25°
2 screws of Ø 5mm.
Weight: 240 g.
All the mechanism composed of ramps and spring  of automatic return, is placed inside the main body of the rising. The mentioned body is placed, at the same time, inside door. Hinge placing: both of the two following ways are correct: at the top or the lower part of the door. In the opposite part it is located the antifriction nylon sleeve where the suitable support axis is inserted inside it. For example ZWTRB
*A double spring is recomended for heavy doors.