Lee Case Length Gauges are a precise, easy way to trim to length and square the case mouth. Used with the Cutter and Lock Stud or Zip Trim. The first step to successfully trimming brass cases with the Lee Case Length Gauge and Shell Holder is to take the Lee Lock Stud (sold separately) and screw it into the shell holder. Next the Length Gauge needs to be screwed into the Case Trimmer Cutter (sold separately). Material: Hardened Steel Features: Caliber specific Shell holder and length gauge