The Trijicon TA11J-G ACOG 3.5x35 Rifle Scope with Green Crosshair Reticle is calibrated for 5.56 (.223 cal) flattop rifles to 1000 meters. The TA11J-G ACOG includes the Flattop Picatinny Adapter Mount. Daytime illumination is provided by fiber optics and Tritium illuminates the scopes at night.