A low-cut sock for the days your feet are going to get warm and stay warm. The yarn is rayon made from bamboo - it moves moisture out and doesn&';t hold onto smell, which matters more on the second lap than the first. Half cushion underfoot. Mesh across the top of the foot. A ribbed arch that keeps the sock where you put it, and cushioned tabs front and back that sit above the shoe line so nothing digs in. Two pairs per pack. Every product purchased removes one pound of trash from oceans and waterways. Fabric. 40% rayon from bamboo, 32% nylon, 23% polyester, 5% spandex. Responsibly made in China. Sizing. S/M fits women&';s 5-8, men&';s 6-9. M/L fits women&';s 9-12, men&';s 10-13.