PREMIUM NYLON MATERIAL - garage door rollers are made of high-quality nylon material and 6200ZZ bearings, which is sturdy and durable, more stable and quieter than metal rollers and other materials, and smoother than previous rollers, suitable for 2 inches garage doors. HIGH-LEVEL DESIGN - The stem of the nylon garage door roller has a galvanized coating to prevent rust. The design of the reinforced double-wall bearing cage and the sealed 6200ZZ ball bearing have the most powerful performance and super long service life. The garage door rollers can more than 10000 cycles under a load of 150 pounds. MORE STABLE AND QUIET -The 6200ZZ precision ball bearing on the nylon garage door wheels rotates smoothly and the high-quality nylon material reduces noise greatly, which can reduce the noise of your garage door by 75%, ensuring your garage door runs smoothly and quietly. You can use it with . EASY TO INSTALL AND STANDARD SIZE - The garage door wheels are easy to install and replace. You can throw the old, worn, noisy or damaged rollers and replace with quiet new garage door rollers. The actual diameter of the garage door roller is 1.81 inches and the thickness of the rollers is 1/2 inch, which fits the 2-inch track in most garages doors. Colour:White Material:Nylon + metal Size:120x46mm Package Contents: 12 * Nylon Garage Door Roller Only the above package content, other products are not included. Note: Light and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.