Martin D-12E Koa Guitar With the D-12E Koa in Martin’s lineup, now more players can turn their dreams of owning a koa guitar into reality. The back and side of this gorgeous model are constructed with koa fine veneer, which is an environmentally conscious, alternative-wood option, made by bonding koa hardwood to an African mahogany core. The result is the show-stopping look of a koa guitar at a great price. But there is so much more to this guitar. Aside from the legendary Martin tone, you will get mother-of-pearl-patterned rosette and fingerboard inlay, a full-gloss body, a soft-shell gig bag, Fishman® MX-T electronics, and Martin’s Authentic Acoustic Lifespan® 2.0 strings. With all that, the D-12E Koa will undoubtedly become your go-to gig guitar.