Trijicon ACOG (Advanced Combat Optical Gunsight) scopes were designed specifically for combat and sporting applications by Trijicon. ACOG scopes differ from standard magnified rifle scopes in that most ACOG scopes do not use batteries for illumination. Trijicon ACOG scopes are either lit by fiber optics collecting natural light, or by tritium, a naturally luminescent radioative particle.
Trijicon ACOG scopes are available in a range of fixed magnification from 1.5x to 6x, and there are a number of ballistic reticles available (depending on model) from .223 up to 50 caliber rifles. These ACOG scopes are currently in use by the US Army, Marine Corps, and countless law enforcement agencies, as well as over a dozen armed forces all around the world.