Heavy weight capability and Durability made the wheel casters like the VXB009C125BTWFSPU a must use, get your do it yourself object move around from our Toronto biz. Dia. Measured of the caster wheel in metric standard 125mm which is equal to 4.921" inch with imperial units. The wheel has a width of 50mm x 2mm=1.969" inch. The Caster with the wheel from end to end is 195mm = 7.677" inch. This wheel mounting is Top Plate with the dimensions of 180mm x 145mm Top Plate: 12mm+housing: 10mm and holes distance of 140mm x 105mm. This caster wheel core made of Cast iron polyurethane and has a Cast iron polyurethane tire spinning over Precision double ball bearing. Each caster wheel will carry the load of 3307 lb and is Swivel type. Ambient temperature range is -40 to 180 F. FYI, you will need to buy the VXB009C125BTWFSPU in order to get one :).