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 bedtime
6200ZZ 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 cycles
Perfect 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 durability
