You will receive: 12 nylon garage door rollers; ample quantity for daily use and replacement needs, with roller sizes suitable for most residential garage doors. Smooth and quiet: Our garage door rollers are made of premium nylon and 6200ZZ bearings, ensuring smooth operation, high load-bearing capacity, and robust reliability. The premium nylon material reduces noise and ensures your garage door runs smoothly and quietly. Sealed garage door rollers: The nylon garage door rollers feature a reinforced double-layer bearing cap design. The bearing caps effectively prevent dust, dirt, and moisture from entering the bearings, extending the product's lifespan. Correct size: Our black replacement garage rollers are 4.8 inches in diameter, suitable for 2-inch tracks and 4.7-inch long stems. The correct size allows the rollers to run more smoothly on the tracks and fit most residential garage doors. Easy installation: The black garage door rollers are easy to install and replace. With just one tool, you can easily remove the old, worn, noisy rollers and replace them with our new rollers for a quieter environment. Color: As shown in the picture. Material: Nylon. Dimensions: 30.30 x 21.79 x 5.21 cm. Package contents: 12 wheels. Only the above content is included; other products are not included. Note: Light reflections and different displays may cause the item's color to differ slightly from the actual product. The measurement tolerance is +/- 1-3 cm.