The weight of an acoustic piano on its wheels/feet will cause permanent indentations in carpets, and may cause indentations or scuffing on hard floors. Caster cups go under the wheels/feet, spreading the weight to prevent indentations, and protecting floors from scratches & scuffs.
When choosing caster cups, consider that the inside diameter must be wider than the piano’s wheels/feet. And, the wider the outside diameter, the more the weight is spread. For hardwood floors, a soft backing is recommended, to further reduce the risk of scratches and scuffs.
We keep popular sizes and finishes in stock. Please inquire for current availability. Most options can usually be ordered in within 2 weeks.