The playing compass is from B-flat alto to B-flat basso. Cylindro-conoidal bore. Brass. The instrument has a conoidal bore tube of 97 cm. (measuring the tube without the mouthpiece), then a straight cylindrical tube, upon which are affixed eight oval-shaped cylindrical bore branches, arranged in such a way as to add progressively increasing length of tubing. This addition or subtraction of lengths is controlled by a sliding piston with a knob and index finger; in the body of the piston, the upper part of which is made of a solid brass rod, are five (should be eight) holes drilled through; the lower half of the piston is made of a long brass tubing open at the lower end; in the upper end, adjoining the solid portion, this piston has one hole which serves as an outlet for the air. The piston is prevented from rotating by a knob which fits into a long slit in a continuation of the tube in which the piston slides. On one side of this slot are engrave position lines and tonalities from B-flat alto to E-flat only. The inside of the bell is lacquered dark cherry-red with trophies and flower in gold. Drain valve on the tube.