E ♭ / Convertible model. The valve system is 3 pistons. Bell is yellow brass diameter 386 mm, bore size is 17.5 mm, silver plated finish. With 2 blowing pipes.
B ♭ / Convertible model. The valve system is 3 pistons. Bell has yellow brass diameter 366 mm, bore size 16.8 mm, silver plated finish. With 2 blowing pipes.
B ♭ / Convertible model. The valve system is 3 pistons. Bell is yellow brass diameter 443 mm, bore size 18.5 mm, silver plated finish. With 2 blowing pipes.
B ♭ / Convertible model. Valve system is 4 pistons. The bell has a yellow brass diameter of 443 mm, the bore size is first to third = 18.5 mm, and the fourth = 19.5 mm. With 2 blowing pipes.
