Shown below is a custom Martin model called the 000-16K.  This guitar features a 12-fret 000 sized body mated to a 1-3/4 nutwidth mahogany neck with ebony fretboard and wonderful slotted headstock.  The unique feature of this guitar is the choice of woods for the body.  The top is select grade spruce with a very tight grain and gloss finish.  Traditional scalloped bracing and vintage tortoise shell pickguard and herringbone rosette.  The back and sides are constructed of beautiful gloss finished koa, bound in ebony.  The guitar has a clear bright tone and wonderful playability.  This is fast becoming one of my favorite instruments.