Material: The shower door roller is made of stainless steel and PA material, the wheels are made of POM, which is durable and quiet, stable for a long service life. Size: Wheel diameter: 23mm; Wheel width: 5mm; Minimum hole size in glass: 11mm; Maximum glass thickness: 6mm. Screws - With caps for the screws. Spring action, also suitable for curved showers. With a nut and a plastic cover. Application - The glass door roller is suitable for most shower enclosures, prevents the door from swinging. Let the door glide smoothly, effortlessly, and safely. Note: These shower door rollers fit glass shower doors that have a center-to-glass distance of 18mm. Rollers for shower and massage cabins, bathrooms, jacuzzis, and even furniture fittings. With our rollers, door and sliding systems can be easily and smoothly installed. The distance between the center of the hole and the edge of the glass should be 18 mm. Size: Wheel diameter: 23 mm. Glass hole size: 11 mm. Wheel width: 5 mm. Contents: 4