1. Quantity: 4 pieces 2. Color: Black 3. Wheel diameter: 30 mm 4. Aperture: 6 mm 5. Material: Nylon and alloy 6. Mounting plate size: 85 x 45 mm 7. Silent nylon rollers: Our wheels are equipped with silent nylon wheels, which will not cause scratches when sliding and are smooth. You can open and close the door comfortably and quietly. 8. High - quality materials: The sliding door wheels are made of high - strength nylon, high - speed bearings and high - quality alloy substrates. The surface is coated with multiple layers of baking paint, with a thick coating, which is not easy to rust, wear - resistant and durable, and can be used for a long time. 9. Height adjustable: The telescopic upper wheel is easy to install, and the height is adjustable, suitable for various indoor doors and windows. Cylindrical conduit, horizontal rotation structure, and smooth sliding without obstruction. 10. What you will get: 4 heavy - duty sliding door rollers, and the size of the sliding door accessories is 85 x 45 mm. The classic black - and - white color scheme can perfectly match your doors and windows. It is recommended to install 2 - 4 pulleys on each cabinet door. 11. Multiple uses: The multi - functional sliding wheels are very suitable for cabinets, windows, wardrobes, cupboards, display cabinets, etc.