OK, now you guys got me wondering...I've never weighed the PSolar balaclava. I just did and it weighs 2.6 ounces. (I have the BX model)
As for the size, the majority of it is made of about 200 weight Polar Fleece and something that is VERY stretchy. I don't see issues with sizing for anyone.
The face portion is made of neoprene. This is the portion where the goofy looking "mouth piece" thingy is attached. It is removable if need be.
What I find is that the mouthpiece warms the air that I breath and I don't feel the need to wear as many clothes or use a heavier bag in order to feel warm.
It's not perfect, though. The mouthpiece does slightly inhibit the amount of air that I can take in, therefore, I tend not to breath through it when exerting myself too hard. It's GREAT when sitting around camp or sleeping, though!
From the website:
"The Psolar BX Balaclava covers the face, neck, ears and head.
Psolar® and Polartec® The Material Makes the Balaclava
This mask incorporates the Polartec® fabrics Powerstretch® and Aqua Shell ™. Polartec® is one of the most widely used and popular brands of outdoor accessory fabric on the market today - highly acclaimed for its durability and performance.
The Polartec® Aqua Shell® fleece face cover is made of a combination of fleece and neoprene, providing a nonrestrictive fit with four-way stretch that comfortably forms to your face. Windproof and waterproof, it provides good breath ability.
The protective neck and head cover portion of the balaclava is made of Polartec® Powerstretch® fleece. The stretchability provides superior fit for a wide range of head sizes. Powerstretch® is warm soft comfortable and quiet."