A simple bamboo whistle flute.
A flute blown through from one end. Notes are played by stopping holes.
A simple bamboo whistle flute, though the design may be quite ancient. 31.5 cm long, .02 cm thick. 6 note holes, other octaves can be achieved by tightening the breath.
Why not have one on you?
Take it out to the Mountains of Mt Cook, take it to the hall ways of the Auckland University and play with the reverberations of the lovely old architecture? Small enough to carry with you.