B-Stock, Leitner & Kraus B2, Bb clarinet mouthpiece, tip length: 19mm, tip opening 1,22mm, a new material (Zelltec), a new pro mouthpiece, L&K worked close together with A. Willscher, Zelltec is a new kind of a High-Tec material on cellulosebase (specific weight like wood), the new sound-improved bore is the perfect solution for a full sound and an easy speech, B-Stock with full warranty, may have slight traces of use