HIGH QUALITY DUAL LOCKING- The wheels made of the popular Non-Marking polyurethane rubber type, very quiet running, absorbs shock and vibrations. Ball bearing and dual locking bring a max loading capacity and safety. | MAX FLEXIBILITY 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. | HEAVY DUTY BEARINGS- Steel structures body is extremely hard wearing and resistant to dirt, 600 lbs capacity for the pack of 4, Bearing Heavy Duty. | UNIVERSAL USE- 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. | 100% LIFETIME GUARANTEE- If you are not satisfied, extremely quiet and the smoothest rolling wheels you have ever used, we'll give you a 100% refund within 90 days of purchase.