Harmonica Chain, Set of 2pcs, 4 Holes, PLATO (TM) Plato (TM) harmonica chain, set of 2pcs Key of C, Pronunciation Method- Diatonic 4 holes harmonica Harmonica Size : 3.5 x 1.3 x 1.1cm/1.4" x 0.5" x 0.4"(L*W*T) material: aluminum cover plate, plastic comb, brass reed.