This is a buzz screw for the neck screw of a Selmer alto saxophone. The neck screw is an important part that transmits sound and vibration. It is a screw made of "nickel silver," which is hard and has good tenacity. It resonates much better than the original screw, and the response is also improved. It has been used for about 3 years, so there are some noticeable stains, but there are no problems with the quality.