The micrometer adjust screw by Lee Precision replaces the original adjusting screw on any Lee bullet seating die. Infinitely adjustable, allows precision bullet seating depth. Easy to read laser engraved divisions represent .001" one thousandth of an inch. The integrated friction ring eliminates annoying clicks that prevent splitting thousandths. No clicks, just smooth adjustment. Reads just like a precision depth micrometer, record your setting and easily return to them for future use. The micrometer adjuster can be easily transferred to other Lee Bullet Seating Dies, but it is so economically priced, you will want one for every die. Size optionsHandgun covers all common handgun cartridgesRifle covers rifle cartridges 17 cal-338 calLarge Rifle covers rifle cartridges 348/35 cal and larger FeaturesInfinite adjustment allows you to set your bullet seating depth precisely. Economically priced: You'll want one for every dieNo clicks, just smooth adjustment