Thermohair socks are made of 75% Kid Mohair and 25% Nylon Yarn. Crew style sits about 6" above ankle (mid-calf).
 
Small - Men's Size 6/7 Shoe
Medium - Men's Size 8/10 Shoe
Large - Men's Size 11/12 Shoe
 
Kid mohair is hair sheared from the kids, during their first year of life. It is the finest, softest, most luxurious of the mohairgrades and is very soft and comfy.  It's micron count is close to cashmere, giving the socks the softness of cashmere, but the strength of mohair. 
 
Mohair is insulating and wicks away moisture, protecting your feet from the cold in sub-zero outdoor weather.  Over the years they have been worn up every major peak, including Everest and both poles! There is minimal friction on your feet which makes them ideal for blister free trekking. There is no tougher natural fiber that can take the continual foot rubbing that occurs when you walk. They're also great for those working in steel toed boots, spending time in the cold outdoors or for those who suffer from cold feet due to health issues. Some scuba divers wear them in their suits to keep their feet warm in the icy waters. 
 
Also, Thermohair socks are made of renewable fibres and the goats efficiently convert plants from non-agricultural lands to fibre that grows an inch a month. They weigh approximately 80 lbs, and produce 20 lbs of hair per year!
 
Did we mention they're made in Canada?!