Technical description: Blackwood with german silver ferrules and keywork. Five pieces: Original mouthpiece, barrel, upper section, lower section, bell. Mouthpiece not grooved for cord. Curved speaker; speaker tone-hole at the front of the instrument, chimney. Speaker liner projects c 2mm into bore. No tube in thumb-hole. Patent C sharp. 12 keys, 2 rings.
L0: T; speaker.
L1: T; throat A♮.
L2: T; throat A♭.
L3: T; cross E♭₄/B♭₅.
L4: C♯₄/G♯₅; E₃/B♮₄; F♯₃/C♯₅.
R1: T; side F₄/C₆; side trill key for throat A-B♮ and B♭-C.
R2: T + spectacle.
R3: T + spectacle (forked B♭₃/F♮₅); cross B♭₃/F♮₅.
R4: G♯₃/E♭₅; F₃/C₅.
Keyhead type: modern cups.
Keymount type: screwed in pillars.
Rubber on mouthpiece.
Usable pitch: according to Shackleton's notes, A₄ = 452 Hz.