You will receive 12 pieces of nylon garage door rollers. This quantity is sufficient for daily use and replacements. The garage door rollers are sized to match most residential garage doors. These rollers are made of quality nylon material with 6200ZZ bearings for high load capacity and durability. The nylon material reduces noise, ensuring your garage door operates smoothly and quietly. The rollers feature sealed, reinforced double-wall covers that provide extra protection from dust, dirt, and moisture, helping to extend product life. The rollers have a 1.8-inch diameter designed for 2-inch tracks, with a 4.7-inch long stem. The proper size allows for smooth operation on the track and fits most residential garage doors. These black garage door rollers are easy to install and replace. Use one simple tool to remove worn-out, noisy rollers and replace them for a quieter environment. Color: As shown Material: Nylon Size: 30.30 x 21.79 x 5.21 cm Package Contents: 12 x Roller Only the above package content is included; other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture to appear slightly different from the real thing. Measurement allowance is +/- 1-3 cm.