This compact steel wrench is a great time-saver. I use one all the time in my workshop.

If your guitar has a slotted truss rod nut at the heel end - as on vintage Teles and the like - it will enable you to adjust the truss rod without unstringing the guitar or removing the neck. Just remove the pickguard! Straight and diagonal ends mean you'll have sufficient space to do the job.

Compact 3-9/16"' (90.49mm) length fits a guitar case.