You'll hardly feel winter's chill when you wear the ActionHeat AA Battery-Heated Cotton Socks. Built-in carbon-fiber heating panels on the tops of the toes provide strategic warmth up to 130°F that'll keep you going even as the temperature falls below freezing. Plus, the cozy 70% cotton/30% Lycra spandex blend traps heat for even greater warmth. Each sock requires 3 AA batteries (not included) for up to 4 hours of run time. Great for skiing, hiking, hunting, and any other cold-weather activity, the ActionHeat AA Battery-Heated socks allow you to forget about the cold and focus more on enjoying your time outdoors. Unisex. Hand wash or machine wash in mesh bag on gentle (without batteries). Imported.Manufacturer model #: AH-SK-AA-02. Cozy cotton blend traps heat Built-in carbon-fiber heating panels on the tops of the toes Provides up to 130°F of heat for up to 4 hours Unisex