The PS-9250-00 is the perfect upgrade or replacement for your Ukulele. BLACK TUSQ Nuts and Saddles provide clear, rich sound and sustain close to ivory that cannot be achieved with cow bone or synthetic materials. BLACK TUSQ is designed to transmit string vibration to the body most efficiently. Compared to the cow bone, it has more mulsonic ingredients to restore the wonderful sound youve been lost. Note: For some products, the model number has been changed from -00 to -C0. Although the model number is mixed with the product, the part itself is not altered, it is the same product. Installation may require modification to fit individual instruments. The right skill and knowledge are required to handle it. We recommend that you have a professional professional or instrument store. We do not accept any **regarding damage or damage caused during installation.