What's the lightest weight light you'd put on your AR?

There is a lot of info in the Lights FAQ but it's from 2005 so I figured I'd ask.  I'm fine with just a clickie back, don't need a tape switch set up.  I want to keep it as simple and light as possible.  Thanks!

Modlite, the small battery version

I have used most all of them and just keep coming back to a X300 1000 lumen. It is small, easy to press forward with the web of my hand and bright all at a light weight.

Its a good light if you dont mind the cintrils, cr123 only, or the throw which varies depending on version.

Inforce WML is 3.22 ounces with the battery and has nice controls. I have one mounted at 12 o'clock on my SBR and it works nicely in that application. It has a lot of spill and enough throw for working within 50 yards. My experience with Gen 2 Inforce lights has been really good. Had a WMLx on my patrol rifle that had been smashed into door frames and barriers enough the bezel was white when I sold it.

A 300 series Scout light will weigh 3.5-4.5 ounces depending on the mount with the batteries and clicky tail cap. I have an Arisaka 300 with a Malkoff E1HT head, Z68 clicky, and Arisaka inline mount on my 13.9 rifle. Don't know the weight exactly but it is noticeably lighter than my Modlite PLHv2 with an 18650 battery. The E1HT has a lot of throw and can easily ID targets out to 200 yards. I verified this with my range finder. It doesn't have a lot of spill though so for indoor work a standard Surefire KE1F head may work better.

Rechargeables are great and in modern lights like Modlite or Cloud Defensive the batteries hold a charge for a very long time. CR123a batteries are also great. Buy a box of 50 and they have a shelf life of 10 years. I just changed the batteries in one of my HD guns that had an expiration date of 2018 and they only recently went flat enough to need changed. There are pluses and minuses to both types and diversity isn't a bad thing.

LaserMax Manta. I have ball point pens that are heavier.

X300U

Being super lightweight might be the only thing the newish surefire micro penlight-looking weapon light excels at.

I don't really know what else it brings to the table honestly.

It’s my understanding that those lights were developed at the behest of a specific unit to be used in conjunction with a larger IR weapon light.