SIZE: Small (US Men: 4-6, US Women: 5-7), Medium (US Men: 6.5-9, US Women: 7.5-10), Large (US Men: 9.5-12, US Women: 10.5-13), X-Large (US Men: 12.5-14.5). Refer to size chart for more information. WATERPROOF & BREATHABLE: 100% waterproof lightweight membrane prevents the external water molecules from entering the socks. MEIKAN waterproof socks for men and women are designed with breathable Porelle membrane and COOLSUN & BAMBOO fabric to wick sweat away from your skin and prevent foot odor, thus keeping feet cool and dry during sports and exercise. PERFORMANCE COMFORT FIT: Smooth toe seam eliminates bulky seams to reduce abrasion and provide extra blister protection. Deep heel cup style with full wrap prevents your socks slipping into fishing boots or shoes. Specific left and right design fits your feet perfectly with added comfort. Non slip ribbed top keeps the sock stay in place. OCCASION: Made of 100% high-tech material, the seamless, moisture-wicking socks are not only thermal and windproof, but also wear resistant and lightweight. These waterproof socks are especially applicable for backpacking, trekking, camping, hiking, trail running, fishing, mountain biking and other outdoor sports and activities, even in various harsh environments. FUNKY DESIGN: Different from ordinary hiking gear and rain gear, MEIKAN crazy digital printing waterproof socks will brighten up your day with the colorful, young, fashion and fun design. You can even pair it with dull sportwear to make yourself stand out in the crowd. MATERIAL: Outer layer – Tube and Upper (93.1% polyester, 6.9% spandex), Toe and Heel (53% COOLSUN, 34.7% nylon, 10.8% polyester, 1.5% spandex), Sole (34.5% COOLSUN, 22.5% nylon, 41% polyester, 2% spandex). Interlayer – 100% waterproof breathable functional interlining Porelle membrane. Lining – 70% bamboo rayon, 30% nylon.