Our lightest, thinnest, waterproof sock. The original, ankle length, military-trusted Wretham sock. 100% waterproof, our lighter socks are perfect for running, hiking or any activity. The Aquasealz(TM) membrane releases body-generated heat and moisture, while denying the entry of external elements. Natural bamboo lining for added moisture control. Handcrafted in the Sealskinz factory in Norfolk. A sock for warm, potentially wet weather. Technology Outer - Extra-durable nylon exterior, with 4-way stretch for an optimal fit. Mid-Section - Aquasealz(TM) membrane is 100% waterproof. Also highly effective in the release of moisture vapour from inside the sock. Interior - Bamboo lining for added moisture control. A seamless construction, with elastic support on the ankle, providing a close fit. Materials and Construction Lovingly handmade in our Kings Lynn factory, under the guidance of Robbie Greenacre, head of innovation and technical development. a Outer Layer - 94% Nylon, 6% Elastanea Middle Layer - AquasealzA(R) waterproof membranea Inner Layer - 75% Bamboo Rayon, 23% Nylon, 2% Elastane