Warm for winter runs but light and thin, so you can keep wearing your preferred fit of running shoe, even if you like them tight to the foot, UpHill Sport 2 Layer Merino Wool Winter Running Socks are the ideal sports socks for cold weather running, cycling, or even climbing and cross-country skiing. With a thermal grade of 2, the socks are ideal for active sports in cold conditions. These crew length “Winter XC” socks are made with a two-layer structure incorporating the natural warmth and breathability of merino wool. The different layers are designed for effective transfer of moisture outwards from the feet, while still keeping them warm. A fitted heel and elastane grip band in the arch improves fit, and support for the mid-foot, and adds comfort by keeping the sock wrinkle free and in place. A seamless toe prevents blisters, rubbing and irritation. All UphillSport’s merino wool products are made in Finland and are mulesing free.