The samba flute, or: Apito, is the whistle used in samba music and other Brazilian music styles. It is important in organizing and conducting the band. The band leader makes various signals to mark the beginning or end of a specific part of the music and/or movement. Using the two toneholes on each side of the flute the whistler can produce different tones in combination with duration and intensity.
I used to have a samba flute myself when I was once playing keyboard in a band. Only mine was a plastic flute and didn't look as good as the one I've drawn here. I found a picture of this wooden one on the internet and it looked good right away. I don't known if it sounds as good as the plastic one I once had, which sounded loud enough to be heared above the PA, but sometimes you choose for the looks instead of the sound.