Globally recognized for superior craftsmanship and meticulous attention to detail since 1983, Lee Oskar Harmonicas pioneered an interchangeable and replaceable system of reed plates, combs and cover plates that has become the industry's gold standard. The Lee Oskar Harmonicas System features four distinct harmonica models in standard and altered tunings, available in multiple keys, for playing many different musical genres. Major Diatonic Reed Plates (model #1910RP Orange Label): Replaceable Reed Plates for the Lee Oskar Harmonicas Major Diatonic Harmonica (for playing BLUES, FOLK, ROCK, COUNTRY, POP and MORE!): The Lee Oskar Harmonicas System features replaceable reed plates in 18 keys for the Major Diatonic harmonica, which makes it possible to revive your harmonica for approximately half the cost. This simple process involves only three screws, two nuts and bolts. Original comb and cover plates are recycled into the rebuilt harp. Replacement reed plates for the Lee Oskar Harmonicas Major Diatonic are available in these 18 keys (listed low to high): Lo, C, Lo D, Lo E, Lo F, Lo F#, G, Ab, A, Bb, B, C, Db, D, Eb, E, F, F#, Hi G .