Wheels have a hard polypropylene core for strength under a polyurethane tread that combines the abrasion resistance of plastic with the shock-absorbing qualities of rubber. Choose from three caster materials. Pin On Organization Friction on their stems grip ring holds them in place. 4 pack caster wheels for wire shelving units . At Sams Club See it Now. It is meant for use with wire shelving units. Using casters may reduce load capacity to 2400. Maximum load capacity of 350 pounds. Metal hardware with ball bearings allow the wheels to swivel while rolling for reliable predictable control. ULINE offers over 30000 boxes plastic poly bags mailing tubes warehouse supplies and bubble wrap for your storage packaging or shipping supplies. Compatible with other furniture. Amazon Basics 4-Shelf Shelving Storage Unit on 3 Wheel Casters Metal Organizer Wire Rack Black 36L x 14W x 5775H 47 out of 5 stars 35957 5499 54. 4-Tier Black Shelving Unit with Adjustable Shelves and 25