Roller Material: Stainless Steel and Plastic with Brass Arm Wheel Diameter: 25mm and Wheel Thickness: 5mm To Fit Maximum Glass Thickness: 4-6mm and for fit hole size in glass: 8-12mm DIY Replacement: It is easy and convenient for this DIY replacement door knob; you can just take it apart with a screwdriver and replace it with new rollers on the glass doors. Shower door rollers are designed for shower enclosure, shower enclosure, tubs and some designer furniture accessories and with a spring which can also fit curved shower glass. Packing: 4 shower door rollers (2 upper rollers and 2 lower rollers). When shopping, please pay attention to the size and dimensions of the product to ensure that it meets your needs. In the title and , we have provided detailed information about the product, including its features and specifications We want you to be completely satisfied with your purchase, so if you have any questions or concerns, please don''''''''t hesitate to contact us. We are here to help and will do our best to assist you. Thank you for choosing our product. We hope you enjoy it