What You Get:you receive 12 pieces of nylon garage door rollers; The quantity is enough to meet your daily use needs and replacements, the garage door rollers are sized to match most residential garage doors Smooth and Quiet:our garage roller bulk are made of quality nylon material and 6200ZZ bearings, smooth and high load, strong and reliable, quality nylon material reduces noise, ensuring your garage door runs smoothly and quietly Sealed Garage Door Rollers:the nylon garage door roller bulk is designed with reinforced double wall bearing covers, the bearing covers provide extra protection from dust and dirt, moisture from penetrating the bearings; Effectively extend product life Fits Size:our 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 fit most residential garage doors Easy 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 them with our rollers, you get a quiet environment Colour:As Shown Material:nylon Size:30.30x21.79x5.21 cm Package Contents: 12 * Roller Only 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.