This filter, when attached to your L or P series flashlight, produces a smooth beam of red light that will not degrade night vision as white light would. Hunters often use the red filter to avoid spooking game during pre-dawn hours as deer see poorly in the red color spectrum. This filter is also useful for close range, non-tactical applications such as map reading as it reduces the intensity of light output. It is made from heat resistant coated glass with anti roll design.