Vandoren Bb-Clarinet BD4 Titanium; mouthpiece for Bb clarinet (Boehm system); Black Diamond titanium series: limited edition for the 120th anniversary; full and sonorous sound with an enormous richness of color, especially in the upper register; tip opening: 1.155 mm; facing length: medium-long; warm and compact sound; has the same characteristics as BD5 Titanium with a lighter response