Here's what Martin say about the GPC-16E:
Martin has expanded their popular 16 series with the addition of the GPC-16E. Each model in the 16 series is designed with the tone wood that best compliments the body size and shape of that particular model. With the new GPC-16E, which is a Grand Performance size with the depth of a 000, Martin selected solid koa back and sides to enhance the easy, natural resonance of this guitar, making it great for recording.
- BODY SIZE: Grand Performance 14-Fret (000 Depth)
- FINISH TOP: Gloss
- CONSTRUCTION: Simple Dovetail Neck Joint
- BACK & SIDE FINISH: Satin
- BRACING PATTERN: Forward-Shifted X-Brace
- SCALE LENGTH: 25.4"
- BRACE SHAPE: Scalloped
- FINGERBOARD WIDTH AT NUT: 1 3/4''
- TOP MATERIAL: Sitka Spruce
- NECK SHAPE: Modified Low Oval
- BACK MATERIAL: Koa
- NECK TAPER: High-Performance Taper
- SIDE MATERIAL: Koa
- ELECTRONICS: Fishman Matrix VT Enhance NT2