When it absolutely, positively needs to be quiet. Specially designed dual grip ring technology eliminates excessive noise, providing quiet mobility. Designed to fit most metal base furniture. Standard Duet Casters—Soft polyurethane wheels for hard flooring and chair mats. Caster/Glide/Wheel: Caster; Color(s): Matte Black; Color Family: Black; Stem Type: Grip Ring Type R Stem.