150mm Flexello Top Plate Swivel Castor and Swivel & Wheel Brake (Heavy Duty Pressed Steel) with 140X105mm Fixing Bolt Hole Centres. Nylon Wheel with a Roller Bearing. Load Capacity = 520kg. Recommended Maximumm Total Load over 4 Castors = 1560kg : 3 x Load Capacity of Castor (520kg)
The 55 series castor is made from heavy duty pressed steel with a bright zinc finish and has roller ball bearings in the swivel head.