Woodi Rosewood Piano Caster Cups WPA-15 Set of 3 Unfinished 5.25" Designed for use with pianos Made of High-Quality Select Rosewood, 3 cups in 1 package. Protects wood, tile, and carpet from piano caster damage Dimensions: 5.25" - outside diameter, 2.75"- inside diameter Underside of each cup is lined with felt pad