The IR window attaches perfectly to a TLR-1 HL tactical light, with no visible light leakage detectable. I can't speak to how durable the rubber hinge is or how it would hold up to heavy use, because I am not putting this through heavy use, but the rubber seems sturdy enough (could the rubber crack or fail later on? don't know). I use this as supplemental illumination for a PVS-14 monocular to spy on wildlife at night, and even though the visible light output of the Streamlight is 800 lumens (blinding), when passed through the IR filter the IR lighting effect is understandably quite diminished compared to the unfiltered visible light output as viewed through the night vision monocular. Viewed through the monocular, the IR-filtered Streamlight will illuminate a darkened room the way a weak flashlight would, but I can't say how far it would penetrate a pitch-black outdoor scene, which I don't have around here. But if you make the light source brighter than this, then you might create a faint dull-red glow light signature, since IR filtration is never 100%. If you stare into the IR filtered Streamlight while in pitch darkness, you can in fact see a faintly visible dull-red glow if you are quite close up to the light, but probably not from across a room. Can't say how this would meet the needs of a professional who relies on night vision in critical situations.