Back from the range.
Xenon bulbs are incandescent.
I did not know that. I stand corrected.
I just got back from the range where I was test firing my new .45 with and without the Z-5 tac-light. Lo and behold, the Z-5 did not break under the recoil. In fact, the added weight on the muzzle-end cut the size of my groups in half (first time out with a brand-new pistol, remember).
When I first got the Z-5 it was shining off to the right a little because the bulb/reflector/bezel assembly is tightened down onto a screw on the left side of the light's interior which carries current from the battery. I used a wadded up bit of paper on the right side to balance it out, and now it shines straight out.
My only complaint is that occasionally when turning the unit on i have to lightly slap or shake it to get it to light up. This is probably caused my a poor connection somewhere and I can probably fix it. It did stay lit through firing with no problems at all.
If you're looking to save money the other guys are right, scope ring with a 1" diameter flashlight will suffice. The only reason I went with the Z-5 instead is I wanted to be able to attach/remove it without having to turn a thumbscrew.
And to answer your original question, it will fit a weaver rail. It also fits picatinny (don't think there's much difference) and glock rails, according to the documentation (which is written in very bad english).
Side note: I noticed the batteries included with the Z-5 read "risk of fire and
bum," so now I'm wondering if I'll wake up in the middle of the night to find them holding cardboard signs and asking for change.