The TB704 RS Berkeley F Attachment Trombone is the step-up instrument for advancing students ready to tackle the extended lower range and professional repertoire that an F attachment enables. A handspun red copper bell, .525" bore, nickel hand slide, and a precision machine tapered rotor provide the warm, resonant tone and smooth action that serious Intermediate trombonists need. Housed in a plush-lined wood case, it's a well-built instrument for advancing studio and ensemble work.