This sight is most popular among shooters who prefer the fastest possible target acquisition. With a viewable lens width of 40mm it provides the largest viewing area of all our optics providing 90 feet of viewable terrain at 100 yards. Built for both-eye-open shooting for rapid targeting and tracking. The optic offers 4 different reticle types with 9 different brightness settings. Red or green reticle colors are offered to accommodate different lighting conditions. Allen key is included for windage and elevation adjustments. The Predator V2 Reflex Sight has an integrated picatinny rail mount with allen key included for tensioning. A 45-degree offset mount included for use as a back up sight alongside your magnified optic. 1 set of LR44 batteries plus an extra set of batteries included for 5,000 hours of usage at lowest brightness level.