The SureFire FM14 Diffusion Filter is a flip-up diffusion filter that is dedicated to flashlights with a 1.62" bezel.
The FM64 converts the prefocused beam of your SureFire flashlight into a softer wide-angle beam for close up work, map reading, or searching in the bottom of your gear bag for your keys.
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.