Dunlop GrooveTech Sound Hole Truss Rod Wrench 5mm

Most acoustic guitars require truss rod adjustment through the sound hole, sometimes past one or two braces to an unseen nut. As a result, normal hex wrenches are not practical. CruzTOOLS GrooveTech Sound Hole Truss Rod Wrenches were designed specifically for this application, with blade length optimized to fit within the sound hole opening and long enough to reach even the most recessed nuts. A specially designed ball-end tip allows easy seating into the nut, and a pro-grade alloy using tight manufacturing tolerances prevents any chance of damage. Finally, an oversized screwdriver-type handle provides confidence when making truss rod adjustments.

Two sizes are available: 4mm fits most makes of guitars, while 5mm is primarily for Martin guitars.