Gretsch G6137TCB Panther Center-Block The coolest new guitars on the block are Gretsch’s new “center-block” models. Each distinctively designed instrument boasts “That Great Gretsch Sound” with a solid new sonic advantage in the form of a special spruce center-block design. These new Gretsch guitars include the G6137TCB Panther Center-Block (pictured), and the G6139CB Falcon™ Center-Block Single-Cutaway and G6139T-CBDC Falcon Center-Block Double Cutaway models, with more to come. All are distinguished by classic pickups and special “thinline”-style bodies (1 ¾” deep, which is unusually thin for a Gretsch hollow-body guitar).