Designed so the user can control and/or change the amount of neck sizing the cartridge case receives.Uses interchangeable sizing bushings that size the outside of the case neck. The conventional expander is eliminated improving concentricity and prolonging brass life.**NECK DIE BASE SOLD SEPARATELY**The die is used with an Arbor Press. Sizes the neck to 3/16" from the mouth end a practice many shooters prefer. Bushings not included. Dies include a de-capping rod. Keep Cases Fire Formed as Possible with the L.E. Wilson Neck Sizing Die Wilson is one of the few that make just about every size of bushing enabling you to keep correct neck tension on your cases.