the second version of our IBTLongsleeve has been adjusted for a more contemporary fit that allows for easier layering and more airflow.
engineered for cold-weather performance.
built with COOLmatic | EXP DIAMAfleece lite™, a lightweight fabric we developed with our Japanese mill, this long sleeve features a smooth outer surface and a soft brushed diamond grid on the inside for comfort.
embedded with carbon yarn, it enhances temperature regulation and odor control, making it the idea item to layer with our HLSTShirt for chilly runs or a standalone piece on milder days.
a bonus, this product can be flipped inside out midway through a run, giving you less loft and accelerated breathability to shed excess heat.

lightweight, breathable, and versatile, this piece is designed to keep you moving through the cold even as you heat up.