Pack of 8 shower door rollers (4 upper and 4 lower). Diameter of rollers: 25 mm. Width of rollers: 6 mm. Minimum hole size in glass: 11mm. Maximum thickness of tempered glass: 6 mm. Materials: plastic, nylon and stainless steel. Supplied with screw covers. Spring mechanism, also compatible with curved doors. With screws and plastic caps. 【Material】: copper rod + plastic + nylon wheel 【Glass size】 5MM. If you need to clamp other sizes of glass, you just need to cut the connecting belt of the glass tank! [Features] Top wheel: adjustable, the wheel can rotate left and right right. The lower wheel has a spring and oscillates from left to right. [Size] Upper wheel: height: 35 mm, width: 27 mm. Wheel diameter: 25MM. Bottom wheel: height: 33MM, total height with buttons: 42MM. Width: 27MM. Wheel diameter: 25 mm. 【Hole Spacing/Aperture】 glass margin: 19 mm. Opening: 10MM -12MM. Pulley diameter: 25mm Reminder: You can adjust the pulley, turn the screw clockwise or counterclockwise with a