1. shape design fits your metal thumb rest perfectly. 2. Thumb finger rest is made rubber material, with high flexibility, comfortable wearing . It is tear-resistant and durable. 3. It makes you feel comfortable, easy to use. For 14.5~17.5mm Diameter Thumb are suitable universal. 4. Rubber protector can be eliminate thumb , protect extra thumb rest and protect your instruments and hand. 5. term to rest your thumb and bring you better playing performance. Thumb Rest Size: (L x W x H): . 27 x 16 x 20mm / 1.1 x 0.6 x 0.8inch Protector Size: 20 x 15MM / 0.8 x 0.5Inch(Dia x Thick) Model Number: Thumb Rest color:Silver Material:metal+rubber Package Contents: 1 x Thumb Rest 1 x Rubber Cushion 2 x Screw Only the above package content, other products are not included. Note: Light 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.