The flute is wrapped with Onikaba (natural birch tree thread) at both ends. The onikaba flute is Rippei's original item.
The flute is tuned to a pitch of "B-flat" however, all Japanese handmade flutes require meri-kari techniques.
(Move the flute away from your lips to raise the pitch, and move it toward your lips to lower the pitch.)
You can also listen to the audio here.