Mammut's lightest and most technical first layer is a true multi-sport MVP. Airy and breathable with offset merrow stitching, its barely-there feel is enhanced by body-mapped mesh and natural sweat-wicking properties for optimal temperature regulation. Quick-drying and odor inhibiting to keep up with your sweatiest challenges, its reflective detailing keeps you visible when the sun gives in before you do. A staple racerback for every outdoor enthusiast.