The storm-ready Callahan fleece is a multifunctional baselayer, and a must-have piece for every winter wardrobe. Thumb loops and a deployable facemask give you the option to maximize skin coverage, and the stretch fleece fabric is woven with NanoRed® polyester, controlling body heat to regulate temperature, improve blood circulation, and stave off fatigue. The Callahan also features Polygiene® odor control technology, which fights bacterial growth from sweat and moisture, and the odor that comes with it. Worn on its own in mild weather, or under your favorite snow jacket in cold weather, Callahan's impressive comfort will keep you in it all year round.