Little or minimum effort can be possible on your operator by installing VXB007050RBF just ask your operator to push and pull, but not carry. 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 16mm=.630" inch. The caster dimensions heightwise is 72mm/2.835" inch. Mounted via a Top Plate that has a size of 65X50 and the holes distance of 45mm x 33mm. The Plain bearing design will enable the Grey rubber tire to roll easily with a core made of Grey rubber. Each caster wheel will carry the load of 44 lb and is Fixed type. The caster wheel temperature range = -40 to 180 F. FYI, you will need to buy the VXB007050RBF in order to get one :).