The Bach small shank tenor trombone mouthpiece is among the most popular and reliable in the world. Alto bones (Bach 39) and small bore tenors (.480"-.508" bore like the Bach 6, 8, 12, 16 - lots of jazz and commercials horns in this range) use a small shank mouthpiece. Also using a small shank mouthpiece are medium bore (.525" like a Bach 36) horns. These are common in jazz work, theater work, concert band, brass quintet or even lighter orchestral stuff. A medium bore horn can almost do it all except for true bass trombone parts. If your ax takes a small shank piece, you can't go wrong with this one.