This is a Marbles Arms tang sight (aka Peep Sight) Winchester 1892 and 1894 lever action rifles. It was also installed as a special order on the Winchester 1895s from the factory. It also fits model 53, 55, model 64 and 65. It comes with 3 different sight apertures (1/2 inch diameter with .055 hole; 1/2 inch diameter with .102 hole; 3/4 inch diameter with .032 hole). Hole spacing on the base of the sight is 2.000 inches to 2.265 and the height adjustment is 1.680 inches to 2.015 inches, with an 18 degree angle. Mounting screws are NOT INCLUDED with the tang sight, so if you need those screws they can be purchased in the option box below.