This die body works with Lee's Deluxe Quick Trim Case Trimmer to quickly and precisely trim brass to the correct length at the same time it chamfers the inside and outside of the case mouth. No calipers, measurement or adjustment required. Simply install the appropriate quick trim die in your press and start trimming. Type Case Trim Die In Set 1 Series Pistol Caliber 357 Mag Die Type Trimmer Die Series Quick Trim