The Trijicon TA31F-G ACOG 4x32 Rifle Scope with Green Chevron BAC Reticle is the USMC optic of choice. The green chevron reticle is designed to be zeroed using the tip at 100 meters. The width of the chevron at the base is 5.53 MOA which is 19 in. at 300 meters. This allows range estimation for silhouette targets. Features dual illumination (Fiber optics provides daylight illumination and tritium illuminates reticle at night). The ranging reticle is calibrated for 5.56 (.223 cal) flattop rifles out to 800 meters.