If your planning a long trek this is the sock for you. Made from the unique Mountain Junky odour busting combination of bamboo viscose and wool ultra you have the perfect sock for extended use. The bamboo is extremely soft and comfortable and the wool ultra (merino wool) built in to the pressure areas on the ankle, toe and heel make for an extremely comfortable sock that can be worn in both hot and colder climates such as the desert. I wore one pair of these socks on an expedition in Africa and had the same pair of socks on for 11 day's!