Roller Set: 8 shower door rollers (4 upper rollers and 4 lower rollers). Material: The pulley is made of plastic and stainless steel. strong and sturdy. Size: Pulley diameter: 25mm. Applicable glass size: 5mm. Glass hole size: 11mm. Convenient installation: The shower door rollers are easy to move and install, and are equipped with nuts and plastic covers. Application: The shower door roller is suitable for most shower rooms, bathrooms and steam rooms. Save space and effort.