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.
Neo series. B ♭ / F compensating system. Valve system is 4 pistons. The bell has a yellow brass diameter of 300 mm, the bore size is 15 mm (1st to 3rd) / 16.8 mm (4th), silver plated finish.