Imagine your office chair has no wheel caster, you would be carrying it right and left, install 4inch-Caster-005 instead. This wheel caster has a wheel diameter of 100mm or 3.937" inch in inches. Dimensions of the caster wheel is 50mm (1.969" inch). The Caster with the wheel from end to end is 142mm = 5.591" inch. Mounted via a Top Plate that has the size of 100mm x 115mm and the holes distance of 75mm x 85mm. The caster core is made of Thermoplastic Rubber and has a Thermoplastic Rubber tire with a low friction Double ball beaing. Each caster will carry the load of 441 lb and is Fixed type. Last and not least the temperature range = -40 to 180 F. Enjoy our 4inch-Caster-005, we wish all the best in your project.