This ultralight running jacket features PERTEX QUANTUM ripstop fabric made from recycled nylon for superior wind and water resistance with exceptional tear strength. Stretch mesh panels at the underarms and center back provide ventilation and freedom of movement, while ergonomic sleeve construction follows natural arm motion. The self-stowing design allows the jacket to pack into its own rear pocket for convenient portability. Laser-perforated zones enhance breathability, and reflective elements provide low-light visibility for early morning or evening runs.