Sealskinz Unisex Thin Weight Mid Length Walking Sock Nylon / Elastane Thin weight mid length sock for a multitude of activities, where maximum breathability and calf length coverage are required Totally waterproof, breathable and windproof Merino wool lining for moisture control & comfort Elasticated ankle & insteps offer support and a comfortable fit Material composition: 87% Nylon, 13% Elastane; Hydrophilic Membrane; 51% Merino Wool, 30% Polyester, 15% Acrylic, 3% Elastodiene, 1% Elastane