Lee Smart Lock Breech Lock Bushings 4/pk E3604D76 LEE. 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. Internal o-ring maintains perfect adjustment. Once set you'll never lose position. For even easier installation Lee offers a handy lock ring wrench. Features of Lee Smart Lock Breech Lock Bushings 4/pk: 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 Internal o-ring maintains perfect adjustment Once set you'll never lose position Handy lock ring wrench included Package Contents: Lee Smart Lock Breech Lock Bushings 4/pk Lee Smart Lock Breech Lock Bushings 4 pack. 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. Internal o-ring maintains perfect adjustment. Once set you'll never lose position. For even easier installation Lee offers a handy lock ring wrench. LEE91933