Red light is Used to preserve the eyes natural adjusted night vision; it will disturb eyes the least of all colours which helps your eyes to stay adjusted for night conditions. Red light provides great contrast and is not visible to the human eye over long distances. Photographers use red colored light when doing night-time photography because it provides contrast while preserving the natural shadows developed by darkness. Red light also works well with night vision scopes and goggles, and it cuts through smoke better than white light. It is also beneficial when map reading or navigating, and its used by aircraft personnel, police, and military in night operations because it will not interfere with night vision technology and can't easily be picked up by other people, and hunters use it to avoid spooking game, because deer and some other animals see very poorly in the red colour spectrum.

Features:

• Fits the Olight SR91 LED Flashlight
• Olight Filters and Diffusers outside use a high quality TPU body construction which offers flexibility, durability, chemical and abrasion resistance.
• The lense of the Olight filters are made of ground glass.
• Lenses feature a top quality Anti-Reflective coating on BOTH SIDES for optimum light transmission.
• Offers a lanyard loop for convenience.