Mounting 4inch-Caster-039 is the solution of making your project to move around by pushing. Diameter of the caster wheel is a metric standard 100mm that is equal to 3.937" inch with imperial units. The wheel has a width of 45mm=1.772" inch. The caster dimensions heightwise is 145mm/5.709" inch. Mounted via a Top Plate that has the size of 100mm x 115mm and the holes distance of 75mm x 85mm. Low drag was achieved by a co-polypropylene core on a co-polypropylene tire spinning freely with a Double ball beaing. Here come the maximum load that should be applied on every wheel, remember to add safety factor, when calculating the load capacity 551 lb with a Fixed type. Last and not least the temperature range = -40 to 180 F. Remember, you will have to buy the 4inch-Caster-039 in order to have it :).