Made of high-quality felt material, the texture is moderately soft and hard, does not hurt the strings, is durable, and has a good damping effect. A three sizes perfectly meets the tuning needs of the tuner. When using it, insert that needs damping. Between the space, it prevents other strings from sounding during tuning and causing the tuning to go out of tune. Product:Three sets of orange and white sound stop blocks for grand piano tuning Colour:Orange-White Material:felt Size:16.5x11x2cm Package Contents: 3 * three-size felt Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.