4-pack of universal M6 2-inch swivel casters for server racks/cabinets/4-post racks | Replacement caster wheels or add mobility to a floor rack - Wheel Size: 2"x1.7" (50x43mm) | Cold-Rolled Steel and Plastic | Included Hardware: 18x M6 Screws/18x M6 Nuts/18x Washers | Set of 4 - Heavy duty casters support a stationary load up to 550 lbs (250 kg) or a rolling load of 165 lbs (75 kg) - Caster kit can be used on any rack with a 45mm x 75mm bolt pattern - StarTech.com Lifetime Warranty