Purchased three years ago, but never used. Here's an excerpt from the product description: This is a recommended product that solves the problems of playing a 10-hole harmonica while singing. The part that attaches to the harmonica uses a new method of securing both sides with rubber, making it easy to attach during performance, and preventing the harmonica from shifting or being damaged. Because you can take a deep breath, you can play with a solid, thick sound. Furthermore, it's possible to make fine angle adjustments, allowing you to play in the best position. Silicone washers are used in the rotating parts of the screws, so once tightened, you can adjust the entire thing to your desired position with moderate firmness.