Basically, this is the standard cylindrical inner bore of a clarinet.
Microscopically, however, you can see that it is not parallel-cylindrical, but has a slight parabolic course of +/- 0.2 mm over the entire length of the inner bore.
This innovation combines the intonational advantages of a somewhat narrower inner bore (Ø 14.8mm) with the full and dark sound characteristics of a very wide inner bore (Ø 15.2mm).
This micro-parabolic inner bore gives the oscillating air column in the clarinet more suppleness.
It facilitates the switching between the registers and allows a soft and smooth, flowing legato.
Due to the micro-parabolic inner bore, the sound waves are reflected into an infinite number of facets.
This results in an acoustic fullness, a unique harmonious richness, and a warm, supple and deeply touching tone color.