This is due to the bullet, cartridge case, and seating system are a fitting chamber for the seating operation. With the addition of the ultra-accurate micrometer, the die is able make accurate seating depth adjustments. The micrometer (index marks in 0.001 increments) allows fine adjustments to as small as 0. The ability to fine-tune with the twist of the micrometer side steps the frustration of trial and error. This die is packaged in a cardboard box.