The L.E. Wilson Steel Neck Sizer Die Bushing is made of hardened stainless steel and comes in .001” increments, with a .003” taper for precise neck sizing.
It allows for adjustable tension by flipping the bushing; markings facing down provides a tighter fit for cases with hardened brass or for fine-tuning.
Compatible only with L.E. Wilson dies, it's not interchangeable with Forster or RCBS dies, and sizing can be determined by subtracting .002"-.003" from the loaded cartridge's outside neck diameter or case neck wall thickness calculation.