The comfiest tee to pair with a running vest. Whether you're running in the mountains or on your local trails, the Cirriform Tee's seamless shoulder area is optimized to be worn comfortably under a hydration vest. Mesh body mapping at the body's highest sweat area and quick-wicking fabric provides all day breathability and comfort. FEATURES Mesh back for increased breathability in the body's highest sweat area Reflective logo to help keep you visible when running in low-light conditions SILVADUR(TM) Advanced Microbial Control and moisture wicking Flatlocked anti-chafe seams UPF 20+ Seamless shoulder design for maximum comfort and compatibility with running vests and packs SPECS Weight: 4.70 oz / 133.0 g MATERIALS Primary/Body: 92% Polyester, 8% Spandex Secondary: 92% Polyester, 8% Spandex | Ultimate Direction Men's Cirriform T-Shirt in Navy Size Medium