The descendant of the first technical base layer created in 1984, ME Chamois has developed a reputation for being the most reliable, durable under layer made by our company. The secret to the success of these men's thermal tights lies in the fabric's intimate blend of enhanced polyester and spandex fibers. This piece of men's long underwear is engineered with exceptional stretch-ability in a polyester treated with Bio-Silver anti-microbial silver properties that inhibit the growth of odor-causing bacteria. The result is a highly technical, high-performing piece of thermal underwear that'll keep you warm for years to come. Order these Hot Chillys tights today!Fit Tip - These Micro Elite Chamois men's thermal tights feature a snug, body fitting silhouette for exceptional moisture management. If you are in-between sizes - order up one size. NO fly opening.