An upgrade to the L.E. Winlson standard steel line. Brass has good corrosion resistance and an excellent surface finish, perfect for gaging your cases. One piece gage that will check overall length to indicate the need for trimming, datum to head length to assure correct headspace and to prevent over sizing. Available for most popular rimless cases. The Cartridge Case Gage was designed with safety in mind and was invented by our founder Sam (L.E.) Wilson in 1935 after a fellow shooter approached him for help in solving a case-separation issue. The gage allows you to see just how much you are sizing back your shoulder on your cases. Mfg: L.E. Wilson