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 covers, the 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 , 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.