As part of the Altitude collection, The Arma Tech 1/2 Zip incorporates the moisture management benefits of Synthetic fibers with the superior thermal regulation of merino wool. Made with a Polyester face for moisture wicking and quick dry time and a merino wool backer for temperature regulation through a complete range of environments. By combining polyester and merino wool, this gives the fabric more strength, more stretch, and a smoother finish resulting in an incredibly comfortable next to skin layer. Combine this base layer with the mid-weight Arma Fleece 1/2 ZIP or the Arma Hoodie for maximum performance.