Casters feature either soft, urethane-bonded wheels to be used on hard floor surfaces and chairmats, or hard, nylon wheels to be used when chair is rolling on carpeted surfaces.
Mistakeproof stem selection - each set includes five wheels and 10 stem fasteners (5 each: 3/8"D x 1"L and 7/16"D x 7/8"L) for all metal-base chairs