Our shower door sliding rollers adopt an electroplated plastic alloy that is rust-resistant; on the other hand, while ensuring the strength of the shower door roller slides, the plastic alloy greatly reduces the risk of glass breakage due to collisions.These shower door wheels fit glass thicknesses of 4 to 6 mm and glass openings of 12 to 14 mm, wheel diameter of 23 mm, there are 4 additional anti-collision blocks to best protect your shower door.Adjust the wheel height using the top screw. (7-8mm adjustable)These shower door wheels fit glass thicknesses of 4 to 6 mm and glass openings of 12 to 14 mm. The wheels have a diameter of 23 mm, and there are 4 additional anti-collision blocks to best protect your shower door.A pair of shower door rollers can support approximately 30 to 35 kg. It is recommended to install a glass door within this load range. You can install additional rollers to distribute the load evenly across each pair.It is recommended to replace the plastic shell shower door sliding rollers every six months, and the metal shell pulley is recommended to replace it every year.