Stepped, one-piece, brass gauge measures the choke of 12, 16, 20, 28 gauge and .410 shotguns. Easy-to-read markings clearly indicate Cylinder, Improved Cylinder, Modified, Improved Modified, or Full choke for fast, painless measurement.
Big Book Catalog, Issue:68, Page:512
Mini-Catalogs, Issue:05, Page:007
New Product Supplement, Issue:566, Page:021
SPECS: Brass. 5" (12.7cm) long.