Always Have The Right Aperture For Your Shooting Conditions
Individual Williams apertures let you choose the correct sight for your hunting and target shooting environment. Provides the correct replacement for a missing or damaged disc. Standard length shank fits Williams Foolproof, Target Foolproof, and 5D only.
Big Book Catalog, Issue:68, Page:306
SPECS: 7/32"-40 thread. 3/8", ½" or 7/8" O.D