The Frankford Arsenal perfect seat hand primer will make sure you do not over seat and crush a primer again. It features a dial that adjusts the seating depth .001 at a time with a total adjustment range of .05. Once you have the seating depth set, you can squeeze the handle as hard as you want; with the positive hard stop the primer will never seat deeper than the set depth. The Frankford Arsenal perfect seat hand primer, designed so you can have the perfect primer seat every time.Features:Hard stop so you can never crush a primerWorks with both small and large primersComes with 12 shell holders to cover the most popular casesEntire system stores in a robust injection molded caseHeavy duty cast zinc construction with steel internal componentsThumb release easily switches from large to small primersAdjust seating depth by the 0.001 inches increments