Double flageolet. Nominal pitch: B♭ (three-finger tonic).

https://images.is.ed.ac.uk/luna/servlet/iiif/UoEart~2~2~18098~104761/full/,150/0/default.jpghttps://images.is.ed.ac.uk/luna/servlet/iiif/UoEart~2~2~23927~104760/full/,150/0/default.jpg

Video