The AcoustaGrip CELLO Pad fits most sizes from 1/2, 3/4 to full 4/4 size instruments. The AcoustaGrip Virtuoso Red features a distinctive multi-layered design with an added layer for superior moisture control to prevent slippage & instrument damage. One layer attaches simply with air to the back of your cello using micro-air technology and may be attached and reattached repeatedly. Easily fitting inside the case, the Virtuoso is a 3-layer AcoustaGrip CELLO Pad that offers utmost Comfort and Protection against instrument damage from moisture (perspiration), fuller sSound and enhanced feel of vibrations. The beautiful design allows you to effortlessly keep your instrument firmly in place. Each layer is made of special acoustical material, delivering superior sound and utmost comfort without skin irritation or bruising.