Package Includes: you will receive 12 nylon garage door rollers, there are enough quantity for your daily use and replacement, nice choices for your garage door Quiet and Smooth: the nylon garage door rollers are mainly made of quality nylon material and 6200ZZ bearings, which are strong and serviceable, smooth reduce the rotational friction between the rollers and the shaft, making your garage door open and close more quietly and smoothly Sealed Garage Door Roller: garage roller bulk are designed with reinforced double wall bearing covers, cage bearings can also prevent dust, dirt and moisture from seeping in, which can effectively extend the life of the rollers and you for a long time Simple to Install: you can slightly bend the track at the seam to remove, replace the roller, then move the door to make roller (repeat on the other side); Or remove the screws that hold the bracket to the door, secure the cable before undoing the bottom bracket that is under cable spring tension, clip the cable to the track, slide the old roller off, put the roller back in place, and screw in supporting item 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, you will get a quiet atmosphere Practical quite gift:The garage door rollers replacement is made from enhanced nylon, quiet and reliable, which can increase the garage door roller's effectively, as a nice gift to get quiet. Robust and rust proof:The nylon garage door roller is robust and rust proof, the design of the sealed 6200ZZ ball bearing makes it have the powerful performance and long service life, which can perform more than 10000 cycles. Size: Diameter of roller: about 1.8 inches Total length: about 4.65 inches Colour:black Material:nylon Package Contents: 1 set x Nylon garage door rollers 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.