The only harmonica of it's kind currently in production. The Autovalve is unique in that it is an Octave tuned harp where windsaver valves allow both blow and draw reeds to be in the same cell in the comb, as opposed to having separate cells for each reed as in other octave harmonicas. This allows the Autovalve to be much more compact than the typical octave tuned harmonica, yet still deliver that full bodied 'organ-like' tone. Tuned the same as Marine Band style diatonics, the Auto Valve is fitted with wind saving valves which, along with its double reed, octave tuning, produces a tremendous volume and projection. This, along with the wide range of available keys, makes it ideal as an ensemble instrument, be it with Cajun, Polka or String Bands, and gives it the power to stand as an impressive solo model as well. Specifications: 10 double holes, 40 reeds, Keys: A, Bb, C, D, E, F, G, Length: 4 5/8 inches. Octave harmonicas are similar to Tremolo models in reed layout and musical range. Instead of having reeds tuned to the same note, however, each hole has one reed tuned an octave apart from the other. The resulting sound is stronger and full bodied, but without the tremolo effect. This is the harmonica equivalent of a twelve-string guitar and is ideal for regional and international styles like Cajun, Old-Time and Irish music.