You need 4inch-Caster-013 to have your office desk, equipment or even a machine to easily roll them around. This wheel caster has a wheel diameter of 100mm or 3.937" inch in inches. The wheel has a width of 50mm=1.969" inch. The caster dimensions heightwise is 142mm/5.591" inch. Top Plate is the method of installing the caster to your equipment, the dimensions are 100mm x 115mm with the holes distance of 75mm x 85mm. Rolling with a wheel core material of Iron core and Polyurethane and a Iron core and Polyurethane tire rolled over Double ball beaing. Each caster will carry the load of 617 lb and is Fixed type. Last and not least the temperature range = -40 to 180 F. Enjoy our 4inch-Caster-013, we wish all the best in your project.