Beileshi Tactical 3-9x40EG Optics Sniper Hunting Rifle Scope Red & Green Illuminated Gun Scopes Magnification: 3-9X, Objective Diameter: 40mm, Tube Diameter: 25.4mm/1 inch. Field of view: 14-25ft, Click Value: 0~1/4 inch @ 100 yards. Eye Rifle: 2.7-3.3inch, Exit Pupil (mm):4.4-13.3. Reticle brightness adjustable for various shooting condition. Side mount red/green illuminated. Come with rail mounts for 20mm Picatinny dovetail rail Powered by 1pc of 3V CR2032 lithium battery. Tubeless holographic sight with 33mm reflex lens aperture provides a wide field of view, suitable for normal and rapid-firing shooting of moving targets