Redding's Titanium Nitride Neck Bushings are heat-treated steel with a Titanium Nitride coating for increased hardness and reduced friction.
The bushings are available in a range of sizes from .185" to .368", in .001" increments, with the specific size indicated by the last three digits of the part number.
This particular bushing has a diameter of .316 inches, suitable for precision reloading applications within that size range.