SealSkinz Runton WP Cold Weather Mid Length Sock + Hydrostop Black, L

The Aquasealz membrane is 100% waterproof sits underneath the nylon-stretch blend to keep us dry while merino wool blend sits next to skin to wick away moisture and add some insulation to keep our feet warm. This 3-layer construction provides warm and breathable waterproofing to protect our feet and our core temperature from the elements as we're hiking, mountaineering, backpacking, or mountain biking in cold weather.