I ordered this picatinny mount to install on my Marlin Centennial 39 because my wife loves this rifle but as we are experiencing aging eyesight, to clearly see both sights AND the target is an impossible challenge. It fit and mounted perfectly, as did the red dot attached to it. First range trip with said EGW rail and optic produced 2" groups at 50 yards, very stable set up. I very much appreciate this rail being available and made really well!