Neo series. B♭ compensating. The valve system is a 4-piston. The bell is yellow brass with a diameter of 300mm, a bore size of 15mm (first to third)/16.8mm (fourth), silver-plated. Model with main trigger. Neo series. B♭ compensating. The valve system is a 4-piston. The bell is yellow brass with a diameter of 300mm, a bore size of 15mm (first to third)/16.8mm (fourth), silver-plated. Model with main trigger.