The Redding Competition Bushing Neck Sizer Die Set includes a Competition Bushing Neck Sizing Die, Body Die and Competition Seating Die. Both the Bushing Neck Sizing Die and the Competition Seating Die feature micrometer adjustments for precision. Bushings and Shellholder sold separately.Competition Bushing Sizing Die -- With this die, the cartridge case is completely supported and aligned with the sizing bushing before the sizing process begins. As the sizing process starts, the cartridge case remains supported in the tightly chambered sliding sleeve as it moves upward while the resizing bushing self centers on the case neck. The decapping rod is maintained in precise alignment by using the internal parts of the die as a linear support much like a firing pin. While the micrometer adjustment of the bushing position delivers precise control to the desired amount of the neck length to be sized. (Bushings are sold separately)The Body Die -- is designed to full length resize the case body only and bump the shoulder position for proper chambering without disturbing the case neck. It is intended for use only to resize cases which have become increasingly difficult to chamber after repeated firing and neck sizing.Competition Seating Die -- The bullet guide to seating stem fit is so precise that the seating stem can actually be demonstrated to float on a column of air. The micrometer is calibrated in .001"; increments. It also has a zero set feature that allows you to zero the micrometer to your rifle or favorite seating depth.