PREMIUM WARMTH AND COMFORT: Our heated socks feature thick high-quality lining that provides ultimate insulation, for superior heat retaining properties. The inside of our heat holder socks is heavily brushed to ensure a soft feel on the foot and the highest comfort COLD WEATHER PROTECTION: Our heating sock can be worn outdoors to keep your feet comfy and warm in boots, or indoors as your new favorite slipper socks. Ideal for your outdoor adventures, walking and hiking in cold climates and cozy winter days at home. Available in classic black in a 2-pack. Available in sizes 35-38, 39-42, and 43-47 // Small - US Women 5-7 / US Men 3.5-6, Medium - US Women 8-10 / US Men 6.5-8.5, Large - US Women 11-13 / US Men 9.5-12.5 DESIGNED IN DENMARK - MADE IN EUROPE: Our Danish Endurance design team develops these cold weather socks in Copenhagen, Denmark. The production facilities are located in Portugal, where we ensure fair working conditions. These socks are OEKO-TEX standard 100 certified to ensure they are free from harmful substances RECOMMENDED BY EVEREST CLIMBER AND ELITE ATHLETE: This cold weather gear is developed with mountaineer Rasmus Kragh, the first Dane to climb Mount Everest without the use of supplemental oxygen in May 2019. During his training and excursions, Rasmus is continuously testing our socks to ensure the highest standards of performance and material endurance EXCELLENT CUSTOMER SUPPORT: We want our customers to be happy - In case you have any questions or issues, do not hesitate to contact us. Our customer service team is always ready to help you and find the best solution for you PREMIUM WARMTH AND COMFORT Our thermal heat socks feature thick high-quality lining that provides ultimate insulation, for superior heat retaining properties. The inside of our heat holders is heavily brushed to ensure a soft feel on the foot and highest comfort. Our heating sock can be worn outdoors to keep your feet comfy and warm in boots, or indoors as your new favorite slipper socks. Ideal for your outdoor adventures in cold climates and cozy winter days at home. Material: 77% Acrylic, 13% Polyamide, 9% Polyester, 1% Elastane. All materials are OEKO-TEX certified to secure you that our socks are free from harmful substances. Wash & Care: Should be washed at max. 30°C or 86°F. Wash with similar colors. Do not bleach. Do not iron. Do not tumble dry. Do not dry clean. Available in 2-pack in black, in sizes 35-38, 39-42, and 43-47 // Small - US Women 5-7 / US Men 3.5-6, Medium - US Women 8-10 / US Men 6.5-8.5, Large - US Women 11-13 / US Men 9.5-12.5