Monstrum Tactical 3-9x40 First Focal Plane (FFP) Rifle Scope with Illuminated BDC Reticle and Adjustable Objective High precision tactical rifle scope with 3-9x magnification, a 40mm objective lens, and an eye relief of 4-4.5 inches Functionally designed first focal plane rangefinder reticle, with easy-to-read ranging information that remains constant regardless of magnification, for faster range estimation and holdover correction Equipped with an adjustable objective lens - or AO - that allows for sharper focus of the target image, elimination of parallax, and range estimation Touch-button controlled reticle illumination in both red and green with multiple brightness intensities, for better reticle visibility at night or in low light in environments Package also includes set of medium profile picatinny scope rings, a detachable honeycomb filter sunshade, a set of bikini-style see-through lens covers, a felt drawstring carrying bag, a lint free cleaning cloth, and one CR2032 3V battery