Wheel casters like the 2inch-Swivel-Caster-006 are used to roll your built machine or equipment back and forth. Diameter of the caster wheel is a metric standard 50mm that is equal to 1.969" inch with imperial units. The wheel has a width of 50mm=1.969" inch. The caster dimensions heightwise is 48mm/1.890" inch. This wheel caster can be mounted using a with the dimensions of 38mm x 38mm and holes distance of 129mm x 74mm. The caster core is made of Polypropylene and has a Polypropylene tire with a low friction Roller bearing. Bearing in mind that every caster wheel has the load capacity of 77 lb with a Swivel type. The temperature range is -40 to 180 F. Remember, you will have to buy the 2inch-Swivel-Caster-006 in order to have it :).