Imagine your office chair has no wheel caster, you would be carrying it right and left, install 5inch-Caster-011 instead. This wheel caster has a wheel diameter of 125mm or 4.921" inch in inches. The thickness of the wheel is 30mm or 1.181" inch. The overall height of the caster is 155mm or 6.102" inch. This wheel caster can be mounted using a Top Plate with the dimensions of 93mm x 62mm and holes distance of 45mm x 72mm. Low drag was achieved by a Polyvinyl Chloride core on a Polyvinyl Chloride tire spinning freely with a Ball bearing. Each caster will carry the load of 176 lb and is Rigid type. Temperature range = -40 to 180 F. Remember, you will have to buy the 5inch-Caster-011 in order to have it :).