It has two rows of holes tuned exactly one octave apart. When both rows are played at the same time the effect is of two harmonicas playing simultaneously. This enables a single player to achieve a stronger, full-bodied sound not possible with a standard diatonic. Its curved body fits perfectly between your hands. Features moisture-proof synthetic combs, gold anodized covers, and 20 double holes. Key of CIt has two rows of holes tuned exactly one octave apart. When both rows are played at the same time the effect is of two harmonicas playing simultaneously. This enables a single player to achieve a stronger, full-bodied sound not possible with a standard diatonic. Its curved body fits perfectly between your hands. Features moisture-proof synthetic combs, gold anodized covers, and 20 double holes. Keys of C and G.