Little or minimum effort can be possible on your operator by installing VXB007065PVCB just ask your operator to push and pull, but not carry. Dia. Measured of the caster wheel in metric standard 65mm which is equal to 2.559" inch with imperial units. Sizes of the caster wheel is 21mm (.827" inch). The caster dimensions heightwise is 88mm/3.465" inch. This wheel mounting is Top Plate with the dimensions of 65mm x 65mm and holes distance of 49mm x 49mm. This caster wheel core made of Polyvinyl Chloride and has a Polyvinyl Chloride tire spinning over Plain bearing. Having in mind that every caster wheel has the load capacity of 44 lb with a Swivel and Upper Brake type. The Temperature range is -40 to 180 F. FYI, you will need to buy the VXB007065PVCB in order to get one :).