0.2500" first hole diameter 2.1875" overall length outside diameter of right end undercut 2.4900 in. min, 2.4950 in. max od by 0.2500 in. lg 22c solid, external flange one end
Used on 40mm sp anti-aircraft gun,m42/m42a1. 0.4370" overall length 3 holes 0.0979 dia 90 degree countersunk to .125 dia; no 5, 40 unc-2bdrill 22c solid, external flange one end