The Sightmark Ultra Shot A-Spec Reflex Sight premium wide-angle lens system with scratch resistant and anti-reflective red coating, 4 illuminated red reticle options with 10 brightness settings, parallax correction (beyond 10 yards) and unlimited eye relief deliver a crisp, robust field of view and uncompromising reliability, even when perfect sight alignment isn't an option. Built tough, the Ultra Shot A-Spec Reflex Sight is shock proof, IP55 weather-resistant, recoil rated