U-notch, rear sight sets use the highly accurate, 3-dot pattern with two green, fiber optic dots at the rear for sharp contrast and quick sight acquisition in all light conditions. Dovetailed front and rear sights may require minor fitting. For Marlin and Winchester lever action rifles. Replaces factory rear sight. Rear sight is screw adjustable for elevation and drift adjustable for windage. Mfg: Williams Gun Sight SPECS: Aluminum, black anodized. Fits all Winchester and Marlin lever actions with 2 inches behind rear of dovetail cut.