SPECIFICATIONS: MAGNIFICATION: 1x LENGTH: 4.75 IN (12 CM) OBJECTIVE APERTURE: 1.0 IN (25MM) EYE RELIEF: UNLIMITED LENS CAPS X 2 BATTERY: 3 x AG13 BUTTON CELL (INCLUDED) FEATURES: MOUNTS ONTO 20MM RAIL EASY MOUNT TIGHTENING KNOB FIVE LEVEL BRIGHTNESS CONTROL