Features:2Pcs non-slip rubber chair caster cups wheel stoppers floor aurface protector pads.Made of quality rubber that has very good vibration absorbing abilities, prevent any skidding of your furniture.Locks chair wheels in place, cup design that cradles roller and bed caster wheels, prevent the scratches.Protective O-ring bottom protects floors from indentation or damage while holding furniture in place.Use on tables, chairs, cabinets, desks, baby bed, baby carriage and much more caster furniture. Size:Inner Diameter:44mm