Features: * brand new and high quality *Made of high quality material, durable and practical to use *The diameter of the glass opening needs to be 4-6mm. *Suitable for 3-6mm Thickness Glass Doors. *Made of Nylon, Brass and Ball Bearing, it is free of Any Noise and *Have the Advantage of Strong Load-bearing Capacity. *Good Tolerance of Water and Anti-Rust Property. *User-Friendly and Easy to Replace and Install. Specifications: Material: Nylon + Brass + Ball Bearing Color: As shown in the pictures Diameter Size: 22mm Thickness: 6.8mm Package Contents: 4 PCS/8PCS x Brass Shower Door Rollers(Optional) Note: 1. The real color of the item may be slightly different from the pictures shown on website caused by many factors such as brightness of your monitor and light brightness. 2. Please allow slight manual measurement deviation for the data.