The Lee Case Length Gage and Shellholder provide a simple and effective solution for trimming brass cases to consistent lengths, ensuring the highest level of accuracy in your reloading process. To begin, take the Lee Lock Stud (sold separately) and screw it into the shell holder. Next, attach the Length Gage to the Case Trimmer Cutter (sold separately), ensuring that the length gage is set to trim each case to SAAMI specifications. Once everything is securely assembled, insert your empty brass into the shellholder and place the case length gage into the case. Simply turn the cutter until the brass is trimmed to the desired length. This easy-to-follow process allows you to consistently achieve properly trimmed cases with square case mouths, helping to maintain the accuracy and reliability of your reloaded ammunition.