Professional Musicians are using a set of A- and Bb- clarinets in concert and they often have to change between them. Sometimes this change is because of needing a low Eb at the Bb-clarinet, but not because of sound or technique.

For this problem invented Peter Heubeck ( soloist in Berlin) an extension for the Bb-clarinet. It is possible to use the thumb key as low Eb and also to improve low E, becaus of a pivoting lever. It isn´t neccessary to change anything at the instrument, so it is possible bring back the original condition wtihin a few seconds. You only have to put it between bell an lower joint.

Another advantage is, to have a tone hole for the longfingerd h´ and b´.