This is a 1-1/4a ^2 die, and requires a Hybrid or 1-1/4a ^2 Turret on your ZERO (or other press). It CANNOT be used with a 7/8a ^2 Turret or other 7/8a ^2 press.IMPORTANT NOTE – THESE DIES ARE NOT COMPATIBLE WITH STANDARD SHELLHOLDERS, AND REQUIRE A LARGER DIAMETER SHELLHOLDER RIM. IF YOU DO NOT HAVE A ZERO M-SERIES SHELLHOLDER, YOU CANNOT USE THIS DIE. The ZERO M-Series Sizing die is the culmination of years of testing, research, trial, error, frustration, and finally, discoveries.As Reloaders, Area419 knew they needed a die to do certain things, but as the makers of the ZERO Reloading Press, they also learned a huge amount about what other dies did well or did poorly, and what their customers were struggling with on a daily basis.With the ZERO M-Series Sizing Die, Area419 thinks they have produced a sizing die that is capable of producing the finest, match-grade ammunition, as well as being user-friendly to new and learning reloaders.Sizing brass doesn’t have to be complicated. It doesn’t have to require years of trial and error. It just needs equipment, made with the end-user in mind, designed with the understanding that a die is part of an ecosystem of parts. A press, a die, the brass, the rifle – they all have to work together and be designed with one another in mind. This is that. Introducing, the ZERO M-Series Sizing Die.