Material: Shower door roller made of nylon and copper, sturdy and durable, stable in quality and have a long service life. wear-resistant wheels are smooth and low sliding noise. Suitable for: glass door thickness: 4 to 6mm. Dimensions of the hole in the glass: 10-12 mm.Wide Application: Shower Enclosure - Replacement castors for shower enclosures and massage enclosures, bathrooms, jacuzzi and even for furniture fittings. Thanks to our shower rollers, door and sliding systems can be easily and smoothly. Easy installation: Shower door rollers easy to move and install. For repair, only one screwdriver is needed. Product material: copper + nylon 1. Glass opening 10-12MM 2. Glass thickness 4-6MM 3. The diameter of the roller skate can be based on the size you are currently using Quantity delivered: 8 pieces