The wheels made of the popular Non-Marking polyurethane rubber type,absorbs shock and vibrations. Ball bearing and dual locking bring a max loading capacity and safety. Swivel casters rotate 360 degrees which makes turning the mating equipment possible, Is good for transporting light furniture and displays quietly and safely. Steel structures body is extremely hard wearing and resistant to dirt, 1200 lbs capacity for the pack of 4, Bearing Heavy Duty. The wheels can be used for a multitude of applications Including: Flight Cases, Instrument Cases, Display / Exhibition Equipment, Dollies, Tool Boxes, Light Machinery, Equipment Stands, Mobile Workstations, Speakers, Cabinets, Stands, Amps, Electrical Enclosures, Furniture etc.