A slotted bone nut for guitars with a 43 mm nut width, which covers most Gibson and Epiphone electrics and many acoustics. It measures 43 mm long, 6 mm thick and 9 mm tall, with six straight string slots already started, so the job is fitting the base and deepening the slots to your string gauge rather than cutting from a blank. Bone is denser than the plastic on most factory guitars and is the usual upgrade for sustain and tuning. Dr Parts part number VGP43.