Diagrams and explanation of the 16 note, 32 reed, tremolo harmonica.
Tombo also makes an 8516 and a 9516. These are 16 note octave harmonicas. The 8516 is scale tuned. The 9516 is Richter tuned. The first blow note on the octave harps is not a true octave, just the same note twice to use for harmony or rhythm.