Makes M5 round steel truss rods 2-way adjustable! The brass anchor is fixed to the wood, so the nut can push or pull the rod, depending on the direction of rotation.
The Dunlop System 65 Uni-Wrench is great tool for tightening and loosening any threaded nut on a guitar or bass. This includes pots, jacks, bridge posts, rounded knurled nuts on selector switches and more.