Change brightness setting easily to match ambient lighting conditions with the Trijicon ACOG ECOS 4x32mm LED Scope. This optic gives users much more flexibility in setting up their sighting system right for their environment. The Trijicon ACOG ECOS 4x32mm LED Scope is powered by a commonly available AA battery, which offers an incredible battery life of 12,000 hours on a mid-range setting. The housing is constructed from rugged, durable 7075-T6 aluminum. Uses Red Crosshair 223 Ballistic Reticle Ships with RM01 RMR red-dot optic Weight: 20.5 ounces Provides 6 different brightness settings An off setting is included between each brightness setting on the Mfg: Trijicon