This is a YAMAHA 66B tuba mouthpiece. There are some scratches overall, as shown in the photos. Rim inner diameter: 31.37mm, Throat: 8.35mm American shank It has a thick, stable rim and feels larger than the manufacturer's specifications. With a shallow cup and a relatively large throat, it seems to work particularly well with the F piston. This model is used by professional players around the world. #tubamouthpiece #tuba #tuba