The Rescue Kit fits the standard truss rods commonly used by Gibson®, Fender®, and the majority of guitars: a single steel rod 3/16″ in diameter with a 10-32 thread (also common on mandolins and other instruments). One end of the rod is anchored inside the neck, and the other end is threaded to accept an adjusting nut. Tightening the adjusting nut pulls the rod tight, which pulls the neck. The threaded end is where a truss rod is most likely to fail: threads become damaged, and sometimes rods break at this point. This is where the Truss Rod Rescue Kit helps by cutting wood to expose more of the rod, and cutting new threads into the exposed rod. Sometimes the adjusting nut is located in the peghead, and sometimes in the heel of the neck. The Truss Rod Kit works in either situation.