Piano Caster Cups Upright Piano Caster Cups Wood coasters Cups Designed for upright pianosHigh-Quality Select Hardwood, 4Cups in 1 Package, 100% of The Solid Wood Production The piano casters have the effect of sound insulation anti-skid prevent shock Designed to be placed under a piano's legs in order to protect floors and carpets Wood material-There is a little different on color each cup mat, this is normal, Size 4.0x2.9x1.9 inch