Redding's Titanium Nitride Neck Bushings are heat treated steel bushings with an additional Titanium Nitride coating to increase surface hardness and reduce friction during sizing.
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 .288 inches, suitable for precision reloading applications within that size range.