This GR trumpet mouthpiece is highly acclaimed worldwide for its accurate intonation and tone quality. It is a signature model of Wayne Bergeron, who is active in Gordon Goodwin's Big Phat Band and numerous studio recordings. This is the "Studio" model, which is also used by Wayne Bergeron himself, among the six signature models. Production has been rumored to be discontinued due to the manufacturer's circumstances, and the supply is unstable. Sales have also ended on Wayne Bergeron's webpage, and it is expected to become even more difficult to obtain in the future. I have kept a few, but I haven't used them, so I am considering selling them. There is a slight dent on the side of the rim where the mouth does not touch (see the blue frame in image 4). This does not affect the playing feel. Also, this has been modified to the Bob Reeves sleeve system, and by using shanks of different thicknesses, you can play with the appropriate resistance on various instruments. A thin #7 shank is included. Please comment if you don't need it. Please feel free to ask any questions or negotiate the price. Thank you very much.