Your go-to for a classic men's midweight base layer, Micro-Elite Chamois is the descendant of the first technical under layer created in 1984. This fabric has developed a reputation for being the most reliable, durable long underwear made by our company. The secret to this thermal underlayer's success lies in the fabric's intimate blend of enhanced polyester and spandex fibers. Our MEC Zip-T is a highly technical, high-performing piece of base layer that'll keep you warm for years to come.