Covert illumination source for navigation - Attaches to Helmet, baseball cap, or Picatinny rail - Uses 1x CR123 battery (not included) - Three function modes: 3 white LED Navigation lights when maximum illumination is called for (19.5 Lumen)/ 2 red LED navigation lights for covert illumination (2.5 Lumen output) / Flashing IR IFF Identification beacon - Three brightness modes - Comes with Picatinny mount, helmet clamp mount, and baseball cap adapter