Designed to maintain the ideal temperature in every circumstance, the PLTN socks are extremely comfortable. They are made from PROLEN® yarn, a fabric that is 50% lighter than cotton, thermo regulating and more resistant to abrasion than wool or cotton. And equally important: PROLEN® yarn has a minimal negative impact on our environment. Material & care instructions: - 93% PROLEN®, 7% Elastane - Machine wash cold 30°C - Do not tumble dry, nor iron