The easy to use Redding Competition Shellholders enable you to perfectly match the headspace of your reloaded ammo to any firearm. Once the proper shellholder is determined, your results are repeatable, and no adjustment is necessary. Each shellholder has a distinct black oxide finish and is clearly marked to indicate the amount it will change case-to-chamber headspace – no special tools or gauges required. Packaged in five-piece sets, of the most popular shellholders, in .002″ increments.