Two-Chambered Flutes (O'odham Style)
This style of flute originates with the Tohono O'odham ("Papago") and Quechan ("Yuma") people in Southern Arizona. These flutes are very similar to the Two-chambered block flutes, except that these flutes do not have a block or bird attached. It is necessary to use one of your fingers to place over the sound hole to produce the sound.
More info: Flutopedia