Caster Kit, Includes 4 5-inch Universal wire shelving casters. Non-marking polyurethane tread, top lock brake, 300 Lb. capacity, resistant to acids & caustics, double ball bearing, operational temp range -45 To 180 F, zinc plated. Universal fits most wire shelving units and shelf carts with 1-inch posts. About Us: BK Resources: a leading supplier of Stainless Steel products, plumbing supplies, commercial gas hoses, and refrigeration. They strive to develop products that are built to last, save time, increase efficiency and offer value to the end user. BK Resources products can be found in leading restaurants, bars and night clubs, universities, stadiums and food trucks nationwide.