Review on Super Bright Yellow Light Led Replacement Bulb Single Mode P60 LED Drop-In Module Design For Surefire Hugsby C2 G2 Z2 6P 9P G3 S3 D2 Ultrafire 501B 502B And Other Hunting Flashlights by Jason Sergeantson

I experimented with the 940nm IR LED and my gen3 night vision, and it had about a throw of 30-40yds. Not exactly earth-shattering performance, and it is pretty diffuse at that point as well. Wouldn't worry much about these causing your tubes to auto-gate, in other words. The bulb turns red, but it's not producing any real amount of visible light otherwise, so I don't see that as much of a problem in this context.In conclusion, this is a reasonable drop-in LED for a personal IR flashlight to be used in tasks like personal navigation, but if you're going to mount it on a rifle, it's pretty inadequate unless you're talking rather close ranges.