Redding's Titanium Nitride Neck Bushings are heat treated steel bushings with an added Titanium Nitride coating for increased hardness and reduced friction.
The bushings come in a range from .185" to .368" in .001" increments, with the last three digits of the part number indicating the size.
This particular bushing has a diameter of .324 inches, suitable for precision reloading applications within that size range.