Cruztools GrooveTech GTMLT1, Guitar/Bass Multi Tool - the first multi-tool for guitars and basses that’s actually useful, without unnecessary gimmicks. Whether you have a USA or imported axe, we’ve got you covered for most bridge, truss rod, and other adjustments. Includes four metric and three fractional hex keys, two Phillips screwdrivers, a 2.5mm slotted screwdriver,. Truss rod sizes are ball-end for easy access. All keys are pro grade, using heat-treated S2 material with a polished chrome finish.