Nylon Wheels: Nylon wheels are just as durable as steel wheels, but tend to roll more smoothly and are significantly quieter, so you won't wake the kids when you get home after bedtime6200ZZ Bearings: Each roller assembly uses a 6200ZZ single-row, deep-groove radial ball bearing made of carbon chrome steel, rated for a 190-pound load and more than 200,000 open/close cyclesStandard Size: These garage door wheels are 1.8 inches in diameter, have a 4-inch stem, and are 4.7 inches long overall, making them compatible with the majority of sectional, residential garage doorsPerfect for Upgrades: Some contractors use inferior plastic rollers that wear out in only a couple years to save money; upgrade your stock rollers for improved performance and durabilityPackage Contents: Each package includes a 1.8-inch nylon garage door rollers 10 pack for use with sectional, residential garage doors with 2-inch roller tracks Replace old and worn out garage door rollers with these roller with nylon wheels and 6200ZZ bearings. Some contractors save money on new construction by using inferior plastic rollers, which wear out in only a couple of years. Both rollers with nylon wheels or steel wheels are a good choice to replace plastic rollers, but nylon garage door rollers are generally preferred. They are just as durable as steel wheels, but tend to roll more smoothly and are significantly quieter than the typical rattle and squeak of steel wheels as they move through the tracks. These nylon garage door rollers use 6200ZZ single-row, deep-groove ball bearings, each of which is rated for a 190-pound load and over 200,000 garage door open/close cycles, ensuring decades of safe and reliable operation. Each package includes 10 1.8-inch nylon garage door rollers for use with sectional, residential garage doors with 2-inch roller tracks.