CPA scope bases are made in low height for either octagon of round barrels. These are milled from solid stock and are carefully polished and blued or color case hardened. They come with 6-48 screws, and are sold in sets of two: rear base with .860" hole spacing and front base with .562" hole spacing. The bases are cup style on one side and Posa on the other, allowing them to fit any external adjustment scope.
