SealSkinz Thin Running Socklet Nylon / Elastane Thin weight socket for a multitude of activities, where minimal insulation and maximum breathability 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: Outer shell - 87% Nylon, 13% Elastane; Membrane - Hydrophilic Membrane; Inner lining - 51% Merino Wool, 30% Polyester, 15% Acrylic, 3% Elastodiene, 1% Elastan