Guitar players may know a little about truss rods and action, but few actually attempt adjustment. That's a shame, because a good setup will improve your performance. The GrooveTech provides everything you need to work on your guitar, plus an Easy Setup Guide that takes the mystery out of the process. Eleven hex keys are color-coded gold for metric and black for inch sizes, and long pattern for easy access. All truss rod sizes are ball end. Also included is a thickness gauge, ruler, capo, cutters, string winder, 6-in-1 screwdriver, and LED flashlight. Tools are lifetime guaranteed and pro-grade