Minimization of possible untoward effects on operator by installing VXB20050NY just ask your operator to push and pull, but not carry. And rolling on wheel that has 50mm diameter/1.969" inch. The thickness of the wheel is 50mm or 1.969" inch. The Caster with the wheel from end to end is 62mm = 2.441" inch. Mounted via a Top Plate that has the size of 34mm x 34mm and the holes distance of 129mm x 74mm. Low drag was achieved by a Nylon core on a Nylon tire spinning freely with a Roller bearing. Each caster will carry the load of 66 lb and is Swivel type. The caster temperature range = -40 to 180 F. Very important notice, you need to buy the VXB20050NY in order to get one :).