This 150mm extra heavy duty castors is made of a heavy duty pressed steel zinc plated, housing a polyurethane wheel mounted on an aluminium centre. This castor wheel runs on ball journal bearings, making the heavier loads easier to move. The foot operated wheel brake simultaneously brakes both the swivel castor head and the wheel. These castors are suitable for a range of heavy duty applications, carrying 454kgs each caster wheel, overall height 200mm 4 x M10 Bolt Fixing Plate. 150mm Apex Heavy Duty Swivel Braked Castors with Polyurethane Wheel