Shorter days and changing leaves bring a new phase of dressing. The Arc'teryx Women's Long Sleeve Phase AR Crew provides a solid foundation upon which you may layer in response to dropping temperatures and rising exertion levels. The next to skin fit reduces excess fabric and bulk for more comfortable layering no more loose fabric scrunching under your arms. The dynamic duo of proprietary materials helps retain core warmth while venting sweat and heat from your underarms. The entire shirt contains encapsulated silver ions to minimize and forestall odor build up, just in case you're wearing the Phase AR Crew for days on end. Built in UPF offers sun protection, and flatlock seams protect you from chafing. Whether you're sitting in the end zone or atop the peak you just dominated, the Phase AR crew works with your layers to keep you warm until you return to home.