For many years, the largest selling quality office chair caster. DIAMOND ARROW, hardened ball bearing swivel construction provides easy action and long life. Supplied with non-marking non-staining GRAY BACO soft rubber wheels for use on hard smooth floors, tile, wood, vinyl tile, concrete, and others.. Equipped with polypropylene, quiet rolling, non-marking, hard wheels for movement on carpets. Oxidized copper finish for wood base chairs and nickel plating for metal base chairs.