USNV Blackout™ Infrared filters block 99% of the visible light spectrum from any flashlight using Krypton, Xenon or Halogen light bulbs. These filters allow a maximum of Infrared output while maintaining extreme covertness. Originally manufactured for the US Military, our filters are designed to meet stringent military standards. The polysulfone blend is known for its strength and ability to withstand extremely high temperatures. When used with a flashlight, our filters will drastically improve the effectiveness of your night vision equipment. Most filters come with a rubber boot that secures the filter to the flashlight, while some filters must replace the existing lens of the flashlight.