Outer Diameter:22mm/8.7 inch Inner Diameter:3.5mm/0.14 inch Thickness:6mm / 0.24inch Color:green Material:wool felt Package Contents: 900 x Piano keyboard washer 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.