Sudrophone baryton. Nominal pitch: C / B♭.
Technical description: Brass, 3-valve, in overall shape resembling an ophicleide. With device unique to sudrophones on bell enabling a membrane to be introduced to add a buzzing effect. Bottom bow removable, secured by ligature. Main tuning-slide extension piece for B♭, overall length 218.Fitting for music card-holder. Valve type: 3 Périnet valves, bottom sprung; alignment by key on piston.