Heavy weight capability and Durability made the wheel casters like the VXB20040BPP2T a must use, get your do it yourself object move around from our Toronto biz. Dia. Measured of the caster wheel in metric standard 40mm which is equal to 1.575" inch with imperial units. Sizes of the caster wheel is 40mm (1.575" inch). The height of the wheel caster is 38mm = 1.496" inch. This wheel mounting is with the dimensions of 38mm x 38mm and holes distance of 129mm x 74mm. The Roller bearing design will enable the Polypropylene tire to roll easily with a core made of Polypropylene. Having in mind that every caster wheel has the load capacity of 55 lb with a Swivel type. The Temperature range is -40 to 180 F. FYI, you will need to buy the VXB20040BPP2T in order to get one :).