The Ralph Sauer Artist Series Professional F-Attachment Tenor Trombone provides you a genuinely unique instrument developed through close collaboration between Ralph Sauer and the craftspeople of S. E. Shires. Its screw-bell collar enhances projection and allows a flat case fitting overhead compartments, while a smaller dual-bore rotary valve maintains bore cross-section. A dual-bore slide produces a large-bore sound with medium-bore effort; a single-bore slide provides an open feel. For the standard slide, leadpipes suit large and small shank mouthpieces.