xDurable polypropylene material, low noise.Housing: Galvanized steel sheet Wheels: black rubberBearing bearing type: plain bearing, material: polypropylene (PP) wheels, steel body xMounting plate: approx. 50 x 50 mm, hole spacing: approx. 36 x 36mm, screw hole diameter: 6.2mm, Wheel diameter (d): 50mm Width (T2): 19 mm, 1 Set = 12 castors Maximum load: 40 kg per roller xcastors 50 mm Casing: Made of pressed sheet steel with double ball bearings in the swivel system, axis of bolt-on wheel, chromated zinc to provide high capacity and long lasting performance. x50mm swivel castor Light Grey Bearing type Roller: plain bearing Wheel Center Material: Polypropylene Tread: Protected by non-marking thermoplastic rubber, 85 Shore A floors and carpets from scratches or dents from heavy loads. xThe item consists of 12 pieces casters and is suitable for workshop , industrial, warehouse, relocation, chairs, tables, storage shelves, cabinets, trolleys, furniture, such as beds, chairs and sofas, barbecue, etc. Note: Due to the light and screen setting difference, the item's color may be slightly different from the pictures. Please allow slight dimension difference due to different manual measurement.