Editing Advanced Combat Optical Gunsight (section)

{{short description|American series of telescopic sights manufactured by Trijicon}}
[[File:PEO Trijicon M150 RCO.jpg|thumb|upright=1.3|TA31RCO variant of the ACOG which is designated as the M150 RCO in [[United States Army]] service]]

The '''Advanced Combat Optical Gunsight''' ('''ACOG''') is a series of [[Prism sight|prismatic telescopic sights]] manufactured by [[Trijicon]]. The ACOG was originally designed to be used on the [[M16 rifle]] and [[M4 carbine]], but Trijicon has also developed ACOG accessories for other firearms. Models provide fixed-power [[magnification]] levels from 1.25× to 6×.<ref>{{cite web |url=http://www.trijicon.com/na_en/products/product1.php?id=ACOG |title=Official Listing of ACOG models |access-date=2011-02-11 |archive-url=https://web.archive.org/web/20110204142409/http://www.trijicon.com/na_en/products/product1.php?id=ACOG |archive-date=2011-02-04 |url-status=dead }}</ref> ACOG [[reticle]]s are illuminated at night by an internal [[tritium]] [[phosphor]]. Some versions have an additional daytime reticle illumination via a passive external [[fiberoptic]] [[light tube|light pipe]] or are [[LED]]-illuminated using a [[dry cell|dry battery]]. The first ACOG model, known as the TA01, was released in 1987.<ref>{{Cite web|title=Acog History|url=https://www.trijicon.com/our-story/trijicon-history|website=Trijicon Acog.com}}</ref>