6inch-Caster-018 is a wheel caster, which is the shortcut of installing wheels on a hospital bed, or any objexct needed to be moved. Diameter of the caster wheel is a metric standard 150mm that is equal to 5.906" inch with imperial units. The wheel has a width of 50mm=1.969" inch. The Caster with the wheel from end to end is 195mm = 7.677" 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 Polypropylene core and Polyurethane core on a Polypropylene core and Polyurethane tire spinning freely with a Double ball beaing. Bearing in mind that every caster wheel has the load capacity of 617 lb with a Fixed type. Last and not least the temperature range = -40 to 180 F. Remember, you will have to buy the 6inch-Caster-018 in order to have it :).