0.1390" first hole diameter 0.3650" overall length 2 holes located on 180 deg line of flange 0.500 in. from centerline tocenter of hole, positioning slot in periphery of flange 0.140 in. w located 90 deg from mtg holes anodize surface treated 22c-2 solid, external flange one end, interior flange (s) not located at either end