Your go-to for classic base layer, Micro-Elite Chamois is synonymous with the Hot Chillys brand. The descendant of the first technical base layer created in 1984, Me Chamois has developed a reputation for being the most reliable, durable underlayer made by our company.The secret to the success of this men's thermal long sleeve lies in the fabric's intimate blend of enhanced polyester and spandex fibers. Our unique recipe for this thermal base layer top calls for exceptional stretch-ability in a polyester treated with odor-blocking properties that inhibit the growth of odor-causing bacteria. The result is a highly technical, high-performing men's thermal base layer top that'll keep you warm for years to come.