The D-42K2 was Martin's limited "all Koa" model, and it is an absolutely gorgeous instrument to behold! It sports some typical 42-style appointments (Abalone rosette and top trim, Mother-of-Pearl snowflake fingerboard inlay), but the top, back, and sides are all beautifully flamed Koa. It also features a forward-shifted x-bracing pattern, 1 11/16" nut width, and a very comfortable neck profile. Tonally, it falls somewhere between rosewood and mahogany (to my ears at least) with warmth, overtones, and plenty of punch. Demo video coming soon!