Can't Miss Being "Dead-On" Each Time
Instantly locates exact rib centers for precision sight installation on
most shotguns. Bar rides across barrels of shallow ribbed doubles,
locating pins can be driven back for extra high ribs. Built-in,
hardened marking punch moves freely, won't fall out. Perfect on
vent rib barrels.
Big Book Catalog, Issue:66, Page:494
SPECS: 2" (5.1cm) long, 5/16" (7.9mm) square bar.