Here's what other sites are saying:
Extremely cold days call for the best in protection! The soft and snuggly SmartWool balaclava uses pure merino wool to keep you warm while also managing moisture.
On Sale. Smartwool NTS Mid 250 Balaclava FEATURES of the Smartwool NTS Mid 250 Balaclava NTS Mid 250 fabric Single layer Interlock knit construction Contoured three-panel design with clean finish flatlock seams Comfortable face protection with good peripheral vision
For cold and windy days, don't forget to cover the bits of your face left exposed by a hat and gaiter. Made from Smartwool's Mid 250 Next-to-Skin fabric, the Balaclava keeps you dry and warm while still enabling good peripheral vision.
When the ridgeline above your favorite chute looks like a cresting wave in an offshore breeze, you'll be happy you brought the Smartwool Balaclava as backup. Pull it out, and you'll doubt that it has the nuts for the weather. Put it on underneath your beanie and doubt no longer--thin as it is, the Balaclava's superfine Merino wool is an excellent insulator. It doesn't stifle your head or block your hearing like its thicker fleece brethren, nor will it change the fit of your helmet. What it does is take the sharp edge off the wind, shield your chin and ears from frostbite, and maintain its temperature-regulating properties even if it gets wet. And when the sun comes out, it stuffs back in your pocket without looking like a dinosaur egg.