The original, military-trusted sock, enforced with Hydrostop™. A men's and women's waterproof sock, the Briston thrives in multiple environments. Hydrostop™ prevents water dripping down leg into sock. Lightweight and breathable. Handcrafted in the Sealskinz factory in Norfolk.Specifications:- Outer Layer: 90% Nylon, 10% Elastane- Middle Layer: Aquasealz® waterproof membrane- Inner Layer: 36% Merino Wool, 36% Acrylic, 18% Polyester, 5% Elastane, 4% Nylon, 1% TPUTechnology:- Sealskinz three-layer AQUASEALZ™ composition sees a 100% waterproof hydrophilic membrane enmeshed between a premium merino wool interior and an extra-durable nylon exterior.- Outer: Durable nylon exterior, with 4-way stretch for an optimal fit.- Mid-Section: Aquasealz™ waterproof membrane releases body-generated heat and moisture, while denying intrusion of external elements.- Interior: Premium merino wool and acrylic blend for softness, sweat-wicking and odour resistance.- Hydrostop™: Hydrostop™ is an elastic taping around the inside cuff of the sock. This extra barrier reduces the risk of water dripping down the leg into the sock.Care:- Wash at 40ºC/105ºF- Low Tumble Dry or Drip Dry- Do Not Dry Clean, Iron, or Bleach