The SureFire FM35 Red Filter is a flip-up red filter that is dedicated to flashlights with a 1.25" bezel.
The smooth focused red beam produced by your SureFire flashlight with the FM35 will not degrade or impair your night vision viewing abilities. Outdoor enthusiasts often employ red-light flashlights to avoid disturbing game during twilight hours. This filter also comes in handy for non-tactical applications such as nighttime map-reading, and those predawn raids on the refrigerator.
Thumb pressure on the locking tab releases the cover, and a spring mechanism keeps the open cover flat against the flashlight's housing. A locking lever keeps the entire unit securely attached to the flashlight's bezel.