When your performance actually matters, ditch the cotton tee and upgrade to the Arc'teryx Women's Senna Tank Top. Your torso deserves better than moisture-retaining cotton. This strappy tank offers an outer later composed of the awesome Haven material, a single-knit polyester jersey fabric with spandex for supreme mobility on that precarious rock face or nigh-vertical trail. Inside, the Senna includes a convenient built-in shelf bra with insert pockets for adjustable support and comfort. Composing the shelf bra is Aerial polyester, a lightweight mesh lining with moisture-wicking superpowers. Arc'teryx has treated the Aerial mesh with a Polygiene finish to battle the forces of odor with miniature viking warriors. The Senna sports a full-coverage length to take advantage of its UPF 50+ rating, high quality sun protection.