Material: Shower door roller made of nylon and copper, sturdy and durable, stable in quality with a long service life. Wear-resistant wheels provide smooth operation and low sliding noise. Suitable for glass door thickness: 4 to 6mm. Hole dimensions in glass: 10-12mm. Wide application: Replacement rollers for shower enclosures, massage enclosures, bathrooms, jacuzzis, and furniture fittings. Ensures easy and smooth door and sliding system operation. Easy installation: Simple to install and replace; requires only one screwdriver for repair. Product material: Copper + nylon. Specifications: Glass hole opening 10-12mm, glass thickness 4-6mm. Roller diameter compatible with standard sizes. Quantity delivered: 8 pieces