Originally designed for astronauts to beat the bitter chill of outer space (where the average temperature drops to an incredibly cold -270°C) these socks are sure to keep feet super-warm on freezing days here on earth. Knitted from a breathable nylon fibre with soft, super-fine aluminised threads running through it, they reflect your own natural body heat, maximising warmth and minimising perspiration for cosier, drier feet. Unisex design. Machine wash. Acrylic and elastane.