Halifax or Vancouver our Low priced answert to the heavy weight objects movement, Wheel casters like our VXB20050BPP2R will be rolling your machine or equipment back and forth. Dia. Measured of the caster wheel in metric standard 50mm which 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 mounting is with the dimensions of 38mm x 38mm and holes distance of 129mm x 74mm. The weehl core material is Polypropylene and has a Polypropylene tire with a low friction Roller bearing. Having in mind that every caster wheel has the load capacity of 77 lb with a Swivel type. Ambient temperature range is -40 to 180 F. FYI, you will need to buy the VXB20050BPP2R in order to get one :).