Clarinet. Nominal pitch: B♭.

Technical description: Blackwood with german silver ferrules and keywork. Five pieces: mouthpiece, barrel, upper section, lower section, bell. Black ebonite mouthpiece marked for a ligature not belonging, but fitting. With innovations reportedly made for Christiansen, such as the double speaker with automatic closure of additional hole from L3 downwards. Additional vent opened by break throat A and A♭. Upper section has socket, lower two tenons. L3ring vent for D₄/A₅ in tenon. Extra vent for R1ring. C♯₄/G♯₅ tone-hole on back of the instrument, also through lower section tenon. 17keys, 6 rings. L0: T + ring F₄/C♮₆; speaker. L1: T + ring F♯₄; throat A♮; throat A♭. L2: T + E♭₄/B♭₅ corresponding ring. L3: T; cross E♭₄/B♭₅. L4: C♯₄/G♯₅; F₃/C♮₅; E₃/B♮₄; F♯₃/C♯₅. R1: T + ring B♭₃/F♮₅ via correspondence; side E♭₄/B♭₅; side F♯₄/C♯₆; trills 1-2. R2: T + ring B♮₃/F♯₅ via correspondence. R3: T + ring B♮₃/F♯₅ via correspondence; cross B♮₃/F♯₅. R4: G♯₃/E♭₅; E₃/B♮₄; F₃/C♮₅; F♯₃/C♯₅. Keymount type: screwed in pillars. Keyhead type: modern.