Redding Micrometer Adjustable Profile Crimping Dies are top adjusting to simplify making precise adjustments because any variation in case length and wall thickness both adversely affect proper adjustment. Traditional Profile Crimp Die adjustment is both time consuming and imprecise due to the coarse 7/8 - 14 pitch die threads and the need to re-position the lock ring, this is especially important to users of progressive reloading presses with tight space constraints. The Micrometer Adjustable Crimping Dies have a knurled micrometer barrel situated on the top of the die for easy access and provides approximately A .100" of "on-the-fly" adjustment in .001 Mfg: Redding