With the Lee Precision Spline Drive Breech Lock Bushing 2 pk, a new, easy grip splined drive surface allows easy, accurate and fast die installation in your press. No need for lock rings on your dies with these quick-change bushings. Simply lightly tighten the clamp screw, and split collar will put a vice lock on your die. Loosen the screw, and the die will spin freely. Once set you’ll never lose position. They look so good and work so well, you’ll want them for all your dies. The hex clamp screw requires a 3/32 hex key wrench, sold separately. For even easier installation, it includes a handy lock ring wrench that works with Lee Spline drive lock rings and Breech lock bushings.