2019 Martin D-18, Custom Shop, Sinker model. Absolutely killer Martin Custom Shop D-18, with gorgeous figured Sinker Mahogany! The guitar has been played and the finish is aged and yellowed. Creating a HUGE booming, woody sound that is the ultimate bluegrass or songwriter guitar. The Sinker Mahogany back, sides, neck, and blocks create a great tone with power and sustain! Check out the spec sheet for full details. Amazing Martin!