B-flat to low C, 22 keys, articulated G#, E-flat lever + E-flat to the thumb, automatic octave key, Silver-plated nikel silver and brass keywork, Upper and lower joints in grenadilla wood, Silver-plated brass bell, Bore: upper joint: 23,5 mm / lower joint: 23,4 mm, 2 necks: 1 small bent, 1 large bent (optionnal), Leather pads fitted with metal resonators, Stainless steel needle springs