The 5.5x50 ACOG is one of the highest-magnification configurations in the ACOG family — and the large 50mm objective lens that makes it so capable at distance also creates a larger reflective surface that can betray a shooter's position in bright lighting conditions. The Trijicon Tenebraex KillFlash ARD for 5.5x50 ACOG AC11013 addresses that vulnerability directly with a precision honeycomb anti-reflection filter purpose-built for the 5.5x50 ACOG objective housing. The Tenebraex KillFlash AC11013 is manufactured specifically for the 5.5x50 ACOG objective — not a generic ARD adapted to fit through loose dimensional tolerances. Tenebraex builds its KillFlash filters to precise specifications for each specific optic configuration they support, which means the AC11013 seats correctly on the 5.5x50 ACOG objective bell without gaps that allow forward reflection to escape around the edges or wobble that misaligns the honeycomb filter with the objective lens. Purpose-built fit produces reliable, consistent anti-reflection performance every time. The killFLASH ARD honeycomb structure allows light to pass normally to the objective lens from the shooter's end — the 5.5x50 ACOG functions exactly as designed, with full optical performance and reticle function available behind the filter. From the front, the objective goes dark. The forward reflection produced by the large 50mm objective in direct sunlight disappears completely, keeping the shooter's position concealed from targets and observers who would otherwise catch a glint off the glass. For hunters working in open country and tactical users operating in environments where position security matters, that concealment is a genuine practical advantage. The AC11013 installs directly on the 5.5x50 ACOG objective without tools and stays securely in place through field use and recoil. Trijicon Tenebraex killFLASH ARD for 5.5x50 ACOG AC11013