These extra heavy duty rubber castors overall height 164mm, 5 heavy duty rubber castors, carrying capacity 300kgs each, 4 x M10 Bolt Fixing Plate. Made of a heavy duty pressed steel zinc plated, housing a 5 (125mm ) solid rubber wheel mounted on a strong aluminum centre. This swivel caster wheel runs on ball journal bearings, making the heavier loads easier to move. These heavy duty castors are suitable for a range of heavy industrial applications. 125mm Heavy Duty Swivel Castors Black Rubber Wheel