Whatever you are building needed to be on wheels, here come the 4inch-Swivel-Caster-004. Diameter of the caster wheel is a metric standard 100mm that is equal to 3.937" inch with imperial units. The wheel has a width of 32mm=1.260" inch. The overall height of the caster is 137mm or 5.394" inch. This wheel caster can be mounted using a Top Plate with the dimensions of 95mm x 70mm and holes distance of 75mm x 52mm. The caster core is made of Polyurethane and has a Polyurethane tire with a low friction Ball bearing. Each caster will carry the load of 176 lb and is Swivel type. Last and not least the temperature range = -40 to 180 F. Remember, you will have to buy the 4inch-Swivel-Caster-004 in order to have it :).