The original Trijicon ACOG delivers unprecedented performance and durability with total user illumination control. Now with six levels of brightness, thanks to the ACOG 4x32 LED. Users can select from six adjustable brightness levels with an “off” between each setting, allowing the user to determine how much to illuminate the reticle - even in transitional lighting. Powered by a single AA battery, the LED ACOG can run for over 12,000 continuous hours (on setting #4).