The Outdoor Sport Ultra-Light Mini Sock features SmartWool's 4-Degree Fit System, which secures the sock in place for exceptional performance and fit. Strategic mesh zones offer ample ventilation to keep your feet cool. The reinforced heel and toe provide enhanced durability for long-lasting wear. The 1 x 1 double-ribbed welt and flat-knit toe seam help keep feet comfortable throughout the day. This ultra-light, non-cushioned mini sock is made from a rugged blend of 59% New Zealand Zque Merino wool, 39% nylon, and 2% elastane fabric. Made in the USA.