Features: Brand new and high quality Strong Support - Plastic made upright piano caster cups. Dimensions: 8.8cm outer diameter, 3.3cm inner diameter. Can securely hold and support your upright piano for years. Also works as heavy-duty wheelchair leg protectors and bed leg floor protectors. Designed for upright piano stands, these piano casters should be placed under the piano legs to protect floors, tiles, carpets. Non-slip & Noise Reduction - The caster cups absorb vibrations and reduce noise without scratching wood floors or wood boards. Anti-corrosion - The piano casters protect the piano's metal and brass wheels from rust or discoloration. Package includes 4 pcs piano caster cups. Specifications: Material: Plastic Color: Black/Transparent/White Package Weight: Approx. 88g Inner Diameter: 3.3cm Size: Approx. 8.8 x 2cm Note: Please allow 1-2cm error due to manual measurement. Make sure you don't mind before bidding. Due to the difference between different monitors, the picture may not reflect the actual color of the item. Thank you! Package Includes: 4 pcs Piano Caster Cups