Grid Fleece Balaclava (Patagucci R1 Material) – $6.90

Just threw it up on the scale and it reads 2.1oz.

My head probably fits on the smaller side of the cap size spectrum, but these do have a lot of stretch. Which might fit an 'XL'-sized dome.

Got mine too. It's pretty lightweight. If you hold it up to the light you can see right through it. I don't think I would consider it for "extreme cold weather". It's similar to Cap 2 material.

I have a noggin that most is hard to fit I wear a size 8 to 1/4 hat and these fit me.

I have a 23.5" dome (circumference) and this has enough room for my giant dome. It is stretchy if one needs a little more room.
I will have to respectfully disagree with the above comment that is it not for cold weather and that it is similar to Cap 2 material. It is much thicker than Cap 2 material and surprisingly warmer than one may think it to be. Yes it is breathable because it is supposed to be (grid fleece allows this to happen, this isn't a windstopper like lyrca).
Like I said in my first comment, it is the VERY SAME grid fleece used in the R1 from Patagonia (which is respectively much warmer than a cap 2 piece from my understanding). Cap 2 isn't grid fleece so I'm not sure where this comment poked up from. Please correct me if I'm wrong but a quick google search shows the cap 2 to be a light baselayer and an R1 is more suitable for midlayer (some use it as a base, not I).
Anyhow, I have taken this on numerous dayhikes the passed two weeks and find it to be adequately warm to around 20f if I am active (probably 35f for sitting around if no wind is involved). Add a hooded windshirt and take it to the teens no problem (again, active… you're going to want a warm hood on top of this is you're sitting at camp in below freezing). I also have long hair so that adds extra insulation.

I decided to checkout some of the other clothing options in the Rothco GEN III line.

I ordered items below:

GEN III MILITARY ECWCS JACKET/LINER Medium
GEN III LEVEL II UNDERWEAR TOP Medium –> weight was 366g — 12.9 oz
GEN III SILK WEIGHT UNDERWEAR TOPS Medium
Gen III Level 2 Balaclava

I am about 5'11" 170lbs and the top 3 items were too large (not athletic fit)
maybe a small may have worked better, but I was not going thru any more shipping cost.
The good part was free shipping to my address.

I sent back all except for the Balaclava which fit well and appeared to be fairly warm.
Should work well for cold weather skiing 10deg and colder when paired with ski hat.

I laughed hard at this thread.

Also, what's wrong with the Sunday Afternoon hat styling? Looks like a GREAT hat!!

All that trouble to stay cool and black shorts? Nooooooo

You look like dumbo when you walk into the wind wearing hats like that.