Size: The diameter of the rollers on the wheels is 25mm, their thickness is 5.5mm. Total length: approx. 32mm. Suitable for 10-12mm diameter glass door hole and the door thickness is 4-6mm. Please check the diameter of your old shower rollers and the thickness of your glass door before purchasing. 25mm Shower Door Wheels - Come with 8 PCS rollers to replace the old rusty rollers, to repair your glass door and keep it sliding smoothly. Material: Made of nylon and copper. Provides good elasticity and wear resistance. Compatibility: 12mm thick glass door is recommended. For shower doors and massage cabins, bathtubs, jacuzzis, or any other furniture. Tips: Before installing the shower door rollers, please apply silicone grease (package not included) to the surface of the glass door rollers to extend their useful life.