Black Blue Diatonic Harmonica features an extra-thick reedplates (1,07mm) are recessed into black ABS plastic body, assembled with 5 self-tapping screws, assuring the ultimate air-tight assembly. Cover plates are coated with electrolytic black chrome. 20 reeds. Keys of, Ab, A, Bb, B, C, Dd, D, Eb, E, F, F#G. Just tuned.