Inexpensive and durable, this 4" x 2" phenolic heavy duty kingpinless swivel caster is high capacity and floor protective. Phenolic wheels should not be used in wet or moist applications.Precision raceways and fully heat-treated construction make our 71 Series the ideal solutions for applications exposed to rugged conditions or high amounts of impact and shock. 71 Series are more durable than competitors case or induction-hardened construction, and longer lasting than conventional kingpin designs. These kingpinless casters eliminate kingpin failure, the leading cause of caster failure. Zinc plating provides an attractive, protective finish.