The Hornady Sure-Loc rings allow you to make precise adjustments of all standard 7/8"-14 dies and accessories. They clamp around the whole die so you can't damage threads. They apply constant pressure across the threads to hold the ring in place. Most other die rings lock by jamming a set screw directly into the threads. The wrench flats allow you to remove and replace dies without pliers ruining the lock ring. - Clamps around the whole die - Applies constant pressure across the threads - Lets you make precise adjustments of all standard dies - Wrench flats - For use with all 7/8"-14 dies and accessories