Cruz Tools "Cheater" narrow blade truss rod adjustment tool for vintage guitar & bass slotted truss rod nuts. 

Vintage-style truss rod nuts have very thin yet wide slots and are made of unhardened steel, so normal slotted screwdrivers will cause damage - as evidenced on many vintage guitars and basses. The Cheater Driver has a narrow blade that allows for a quick minor adjustment without removing the neck. Features an oversized handle with extra-long shaft for a firm grip and easy access.