Graph Tech Black Tusq XL Blank Martin Style PT-M100-00 TUSQ is very easy to sand or file and is very resistant to chipping or flaking. TUSQ nuts provide the best tonal link between your strings and guitar neck. Color: Black Thickness: 7/32" (5.74 mm); Length: 1-7/8" (48.01 mm) Height: 13/32" (10.67 mm) Model: PT-M100-00