The J.A. Custom Special 20 Master Harmonica has unique features, including its own serial number. The harmonica features expert reed work, including a unique embossing method, polished & re-profiled reeds and much more. Players will enjoy the authority they have over this instrument, which is capable of loud and crispy regular notes, perfect bends, and great overbends. The coverplates and the comb has been reshaped for extra volume and playing comfort.