What You :you will receive 12 pieces of nylon garage door rollers; The is enough to meet your daily use needs and replacements, the garage door rollers are sized to match most residential garage doors and Quiet: garage roller bulk are made of quality nylon material and 6200ZZ bearings, and high load, strong and , quality nylon material will reduces noise, ensuring your garage door runs smoothly and quietlySealed Garage Door Rollers:the nylon garage door roller bulk is designed with reinforced double wall bearing covers, the bearing covers extra protection from dust and dirt, moisture from penetrating the bearings; Effectively extend product lifeFits Size: black garage rollers replacement are 1.8inch in diameter for 2inch tracks 4.7inch long stem; Proper size allows the rollers to work more smoothly on the track and will fit most residential garage doorsEasy to Install: these black garage door wheels are easy to install and replace, just one simple tool to remove the old, worn out, noisy rollers in your home and replace with new rollers, you will a quiet environmentColour:As ShownMaterial:nylonSize:30.30x21.79x5.21 cmPackage Contents:12 * RollerOnly the above package content, other products are not included.Note: Light reflection 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.