The Forster Full Length Die sets include their Ultra Micrometer Seater die and a Full Length Sizing Die. Forster Full Length Sizing Dies are each equipped with their E-Z Out Expander button which helps keep case necks concentric during the neck expanding operation. It's positioned higher in the neck area than most other dies. This provides support and holds the axis of the neck and case in alignment while the case is withdrawn from the die. The Forster Ultra Seater includes all of the features of the Forster Bench Rest Seater Die above, plus an ultra accurate micrometer adjustment. This micrometer adjustment allows you to adjust bullet seating depth from .0005 inch to .001 inch increments, and makes switching bullets easy - just dial back to your previous recorded setting. Forster Ultra Seaters make fine tuning your bullets to the lands of your rifling simple. These dies use 1-1/4" threads which is larger than the standard reloading die and are intended to be used with Presses similarly threaded like the Forster Co-Ax XL Press.