Contrabass clarinet. Nominal pitch: B♭.

https://images.is.ed.ac.uk/luna/servlet/iiif/UoEart~2~2~81129~186966/full/,150/0/default.jpghttps://images.is.ed.ac.uk/luna/servlet/iiif/UoEart~2~2~81130~186965/full/,150/0/default.jpg