The official socks of the Space Program. Engineered to improve blood circulation and temperature regulation. Constructed from a high quality Merino wool blend, made to wick sweat, protect and keep you dry. The uniquely knitted seamless tube feels like a dress sock and functions as a performance sock. The Space Program socks features: - Elasticated ribbed cuff that keeps the sock up without excessive pressure on the leg (not too tight, but they stay up) - Engineered arch support to prevent fatigue and to keep the sock in place - Reinforced heel with cushioning for durability and comfort - Woven label hand-stitched on to cuff Material composition: 45% Wool, 36% Nylon, 17% Polyester, 2% Elastane Available in size Small and Medium/Large. S/N: 2021.329 Manufactured in the Jiangsu Province of China, on an Italian knitting machine, both are known for producing the highest quality products.