Octave harmonicas are a variety of mouth organs with two rows of tabs. But

Buy at www.musicianscart.com Hohner M2503017 Comet Key C Holes 32 Harmonica with Case,Octave tremolo harmonica,Story Richter,32 Number of Holes,Copper tab 32,Fees Brass 0.9 mm,Housing plastic,Cover Material Stainless Steel,Octave harmonicas are a variety of mouth organs with two rows of tabs. But, unlike the tremolo harmonica, paired tabs octave harmonica is not using similar frequencies, and with a difference of one octave.