Halifax or Vancouver our Low priced answert to the heavy weight objects movement, Wheel casters like our VXB0045100PUF will be rolling your machine or equipment back and forth. Dia. Measured of the caster wheel in metric standard 100mm which is equal to 3.937" inch with imperial units. Sizes of the caster wheel is 40mm (1.575" inch). The Caster with the wheel from end to end is 140mm = 5.512" inch. Top Plate is the method of installing the caster to your equipment, dimensions are 110mm x 100mm x 4mm fork:3.5mm with the holes distance of 85mm x 75mm. This caster wheel core made of Polyurethane and Polypropylene and has a Polyurethane and Polypropylene tire spinning over ball bearing. Each caster wheel will carry the load of 551 lb and is Fixed type. The Temperature range is -40 to 180 F. FYI, you will need to buy the VXB0045100PUF in order to get one :).