Sized to fit a longrifle or Kentucky pistol with a 13/16", or 7/8" octagon barrel. Made in the U.S.A., the dovetail is approximately .610" long, .540" wide, cut to a depth of .050" or this sight is ideal to be fitted in a lifted dovetail. Height from the bottom of the dovetail to the top of the sight notch is 0.27".