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.Specifications and Features: Die cast zinc body with steel internal components Adjustable seating depths of 1 thousandth of an inch Hard stop so you can never crush a primer Primer tray with ridges for primer orientation Works with both small and large primers Comes with 12 shellholders to cover the most popular cases Heavy Duty injection molded storage case