Martin Guitars have announced the release of the 00-18 Tim O'Brien Limited Edition, which will be on display at Summer NAMM 2008 in Nashville.

The Limited Edition 00-18 Tim O'Brien model incorporates some of the Grammy winning country-bluegrass musician's own design ideas. The guitar has the 00 body and the 18 style which includes mahogany back and sides and an Adirondack spruce top. The top is supported with scalloped, quarter inch Adirondack braces and tone bars and a maple bridge plate. A simple, vintage "18" style rosette adorns the soundhole, however the traditional center ring of black has been replaced with a thin strip of select abalone pearl.

The pickguard is a beveled and polished tortoiseshell style and protects the top below the strings. The top and back are bound in black Boltaron and the center back strip of Madagascar rosewood matches the headplate overlay. O'Brien, in a show of support for the use of alternative woods, chose solid Spanish Cedar for the full-thickness "V" neck, which is joined to the body with a traditional "dove-tailed" neck joint.

Perhaps the most unique feature of the 00-18 Tim O'Brien is the guitar's 25½-inch-scale length. Normally you would find this scale only in OM or dreadnought models. In this guitar the extended scale-length adds power and volume.

Each interior label of 00-18 Tim O'Brien Limited Edition will be signed by O'Brien. A portion of the proceeds from the sale of each Tim O'Brien Signature Model will be donated in support of Catholic Charities Refugee and Immigration Services.

In addition to his Grammy, O'Brien has twice been honored as the International Bluegrass Music Association's (IBMA)'s Male Vocalist of the Year.