Piano Caster Cups - Can securely hold and support your piano for years of use. Also works for wheelchair leg protectors and floor protectors for bed legs.Floor Protectors - Designed for piano legs, these piano casters should be placed under the legs of a piano to protect floors, wood, tile and carpet. Anti-Corrosion: Piano casters protect metal and brass piano wheels from rusting or tarnishing. The set includes 4 piano coasters. Long Lasting Use - Pads designed to protect your floors, rugs and carpets. Will not tear or distract the surface under the weight of the piano maintaining proper pedal height.Features:Designed to be placed under piano feet to protect floors and carpets.Advanced heavy duty plastic design.Designed for use with pianos.Protects wood, tile and carpet from damage caused by piano casters.Color: Black.Outer Diameter: 88 mm. Inside diameter: 53mm.Contents:4 x Piano Caster Pads Note: The data are all manual measurement, please allow 1-3cm error, due to the light and display difference, there will be some color difference, depending on the physical item received.