These little square-bodied reed instruments share the same acoustic parameters as larger saxophones, and they produce a convincingly sax-like sound. Depending on the skill of the player, they have a diatonic range of an octave and more, aided by a register hole on the back. Tone hole placement and sizing for such instruments can be done mathematically, but for the most part I tune by ear, placing the holes according to best estimate and then adjusting the hole size for fine tuning. The challenge in making these is getting the slight curvature on the mouthpiece just right in the area where the reed lies over the opening.
In the audio sample, two wooden saxes play a little calypso accompanied by percussion and strings. A video of this instrument can be found among the demonstrations in this youtube playlist.