This is a U.S. military Harley Davidson blackout headlamp. These headlamps were used by the military when out on enemy patrols. It would produce a minimal amount of light so as not to alert the enemy to the soldier's position. This headlamp comes with the original switch which would mount the the motorcycle's handlebars. The blackout headlamp is in good condition. It has not been tested for working condition. The headlamp measures 5" in diameter.