The Bach Stradivarius Artisan Infinity Series F Attachment trombone (axial-flow) model is constructed of yellow brass, and features a hand-hammered Artisan bell with flat rim and soldered steel wire. It additionally has a reverse main tuning slide with yellow brass crook, .547 bore hand slide with yellow brass outside tubes and bottom crook, and Bach's patented adjustable lever system. The Bach Stradivarius trombone 85-year tradition has been in bands and orchestras around the world for decades. Today, The Artisan Trombone Collection, takes the Bach Stradivarius trombone to the next level. With an intense focus on precision, The Artisan Trombone Collection offers superior performance. The result is endless possibilities for even the most discriminating artist.