Features:OOTDTY The are manufactured from nylon, and the center bearing is made from solid-copper. Fully enclosed bearing, water resistant and dust-proof, solid load-bearing.Suitable Glass Thickness: 4-6mm/0.16-0.24inch.Easy to put in and maintenance.They adjust-able up and all the way down to enable the door to be lined as much as mate with the frames.When you slide the door, there isn't any noise and slide smoothly.Suitable for Most Shower Enclosures, Shower Cabins Enclosures.Specifications:Material: NylonWheel Diameter: 27mm (1.06inch)/25mm (0.98inch)/23mm (0.90inch)/20mm (0.79inch)Suitable Glass Thickness: 4-6mm/0.16-0.24inchSuitable Opening Size of Glass Door: 10-12mm/0.39-0.47inchPackage Includes:1x PulleyNote:Notes:Please allow 1-2cm errors thanks to handbook measurement, just be sure you don't mind before you order. Due to the adaptation between various monitors, the image won't reflect the actual shade of the item.