THESE CASTERS ARE IDEAL FOR REPLACING OLD OR WORN CASTERS ON GLOBAL HARDWOOD DOLLIES. INDUSTRIAL GRADE CASTERS HAVE A NYLON BEARING POWDERED METAL BUSHING AND HEAT-TREATED RACEWAY DURABLE ZINC PLATED FINISH HARD RUBBER CASTER WHEELS OFFER HIGH LOAD CAPACITY AND FLOOR PROTECTION SPECIFICALLY DESIGNED AND MANUFACTURED BY GLOBAL FOR THEIR HARDWOOD DOLLIES.KIT CONSISTS OF A SET OF 4 SWIVEL CASTERS.