Size: The roller diameter is 25mm and the thickness is 5.5mm. Total length: about 30mm, suitable for glass door hole diameter 10-12mm, door thickness 4-6mm Please check the diameter of the old one shower roller and the thickness of the glass door before buying. 25mm Shower Door Wheels - Comes with 8 rollers to replace old rusty rollers, repair your glass door and keep sliding smoothly. Material: Made of nylon and copper. Provides good elasticity, good abrasion resistance. Compatibility: 12mm thick glass doors are recommended. Suitable for shower doors and massage rooms, bathtubs, jacuzzi or any other furniture. Reminder: Before installing the shower door roller, please apply silicone grease (without package) to the surface of the glass door roller to prolong its service life.