Wax cast steel, this rear sight has a long base to fit a slot .730" long, .590" wide and .050" deep. Height from the bottom of the dovetail to the top of the sight notch is 0.37". Easily shortened, this larger sight looks right on a big plains rifle with a 15/16" or 1" octagon barrel. Made in the U.S.A. This semi-buckhorn sight is one of our favorites.