This whistle small produces a sound like a typical tremolo as Trrrrrrrr. Built on a single piece of wood and has two openings on both sides of the bezel giving other musical notes, usually 3 tones.
CLOSED PLAY
OPEN PLAY
In Brazil it is very used to taps of Samba or to highlight the proximity of a cut (break) in music, usually used to direct the Brazilian batucada.