The second version of the IBTLongsleeve has been adjusted for a more contemporary fit, allowing for easier layering and increased airflow. Engineered for cold-weather performance, it is built with COOLmatic | EXP DIAMAfleece lite™, a lightweight fabric developed with a Japanese mill. The fabric features a smooth outer surface and a soft, brushed diamond grid on the inside for added comfort. Embedded with carbon yarn, it helps regulate temperature and control odour, making it an ideal layer for chilly runs or a versatile stand alone piece on milder days. The garment can also be turned inside out midway through a run, reducing loft and increasing breathability to help shed excess heat. Lightweight, breathable, and versatile, the IBTLongsleeve is designed to keep you moving through cold conditions, even as your body temperature rises.