Groovetech® Guitar/Bass Multi-Tool. A guitarist’s best friend offering a range of metric and imperial hex keys in multiple sizes, 2 Phillips head screwdrivers and one 2.5mm slotted screwdriver. Includes 5/16" nut driver for Gibson truss rods. All wrenches are pro-grade, heattreated S2 steel with polished chrome finish and ball ends for easier insertion. There’s also a ruler to check neck relief and string action. Packed in a one-piece body that allows easy rotation and storage of components. Blue.