Hornbostel - Sachs
Stopped flutes with internal duct
The air itself is the vibrator in the primary sense. The standing waves are significantly confined within the instrument itself. A narrow duct directs the air stream against the sharp edge of a lateral orifice. The duct is inside the tube. The lower end of the tube is closed. The instrument has no fingerholes.
Stopped flutes with internal duct, without fingerholes
Stopped flutes with internal duct, without fingerholes with fixed stopped lower end
Stopped flutes with internal duct, without fingerholes with adjustable stopped lower end