That's the exact same one I have. Quick tip - you may want to trim back the flaps under the filling hole cover. They're quite stiff and can lead to an amount of spillage!
Don't know if you've ever used one in a lid but they velcro into the chinbar. If you take your lid off forwards it's OK, if you go straight up or in any way tilt it backwards while you lift it off....forehead gouge!
They absolutely can be used as weapon lights and are being sold as such, but my point was that unless you're trying to hunt small game in the woods at night, such a tight beam is a bit pointless.