The Bridgedale Storm Medium Weight Boot Sock is primarily knit from Merino Wool, known for its anti-bacterial, anti-odour and moisture management properties ensuring the sock will keep your feet warm, dry and comfortable. The outer layer sock, made from nylon, protects the Hydrotech waterproof breathable membrane against abrasion from the boot. Lycra knit through every course gives the sock Bridgedale’s performance fit and together with the flat toe seam and elastic arch support ensure the sock remains in place and doesn’t cause any hotspots. The stretch PU membrane and clever matrix lamination process that bonds the three layers of Bridgedale’s Stormsock together ensure they have class leading stretch built right in, wear after wear. Storm Mediumweight Boot Sock