This buckhorn rear sight has a base .377" long, .53" wide. Dovetail 0.050" deep. The top of the notch will be 0.2" above the plane of the barrel. The base may be file fitted to smaller slots. Use this buckhorn rear sight on a 13/16 or 7/8" octagon rifle barrel. Wax cast steel. As-cast, not polished, not blued or browned. Remove the casting gate before hand fitting. Deepen the notch if needed. This part replaces the RS-JDV-S shown in older catalogs.