Glide Heavy WoolWarm Cross Country Ski Sock in Merino Wool Sub zero morning. The track stretches through the forest. This is what Glide Heavy Wool was made for the warmest sock in the Glide family. Flat knit with full terry that cushions every stride and insulates from cold ground. The Merino Wool regulates temperature regardless of pace warm in headwinds, breathable on the climbs. Reinforced heel in polyamide for lasting durability. Knitted in Rshult.