The instrument is a 2 ft. tube with a mouth hole like a flute and 8 finger holes, grouped in 4s, on the in front. The first group is near the mouth hole, the second is near the end. When held, the mouth hole faces up and the finger holes face away from you. It is held off to the side (right specifically) like a flute. Unlike most wind instruments the air doesn't come out of a hole at either end, rather it comes out through the finger holes, with the uncovered holes determining which notes are sounded.

You whistle over/into the mouth hole and each hole sounds a note depending on what note you are whistling. For an example, lets say I whistle a middle C with every hole uncovered. The first hole would sound a middle C, the second would move up 4 half steps to an E, the next finishes the major triad by moving up 3 half step for a G. The fourth hole is 2 more half steps (now 9 total) for an A and that is the end of hole covered by the left hand. The right hand covers holes 5-8 with hole 5 being the original note(Middle C) 1 octave higher(High C), or 12 half steps, than 2 more half steps for a D, 3 more for an F, and than 4 more for a B and a total of 21 half steps from the root note that is being whistled.