The L.E. Wilson Trimmer Case Holder provides the ultimate accuracy and uniformity for trimming your cases. The unique design of the case holder supports the case body, much like a chamber of a firearm. The Case Holders are precisely manufactured for consistent results and repeatability. The case holders can also be used for primer pocket reaming, neck reaming, and deburring with the L.E. Wilson Uniform Deburring tool (sold separately). Case Holders listed for fired cases will work on fired cases only. Holders listed for new cases will work on new and resized cases only. Holders listed as all will work with either.Notes: To use, simply place the case in the trimmer case holder, tap the case head on a firm surface, and place in the trimmer. The case is easily removed by tapping the case mouth..