This larger version is made for a longrifle with a 15/16" or 1" octagon barrel. Wax cast steel, this sight has a long base similar our other Pennsylvania sight #RS-FG-16. However this sight is .430" tall from the top of the sighting surface, to allow sight-in with a tall front sight, and to reduce mirage and heat glare from the top flat, during shooting matches. A .755" dovetail is about .590" wide. Dovetail to a depth of .050", or fit to a raised dovetail.