Package Content: Set of 4 twin shower door rollers (2pcs top and 2pcs bottom).(recommended for 14mm glass hole) Galvanized Door Rollers: 23mm (diameter) top and bottom shower door double rollers, surface plated, anti-rust; Suitable for 4-6mm glass door thickness, 13.5-14mm glass open hole. These Replacement Shower Door Wheels are suitable for most shower enclosures, cabins shower doors and steam cabins, installed at the top and bottom of the shower door, for easy opening and closing. (recommended for 14mm glass hole) No noise to open the shower door and these glass shower door rollers help it slide smoothly. It is easy to install and maintain.(recommended for 14mm glass hole) Due to factors such as manual measurement and display differences, there may be some slight differences between individual products and images, please excuse me.