Fly through mountain trails with this ultralight 8-liter running vest, weighing just 200g (size M) for barely-there feel during long races and training runs. The smart 11-compartment storage system includes dual flask pockets, a stretch cargo area for quick-access gear, waist side pockets, a zippered phone pocket (with emergency whistle on chest strap), front and rear trekking pole attachment points, a main 8L compartment, expandable clothing storage, and an internal zippered pocket. The semi-open main compartment allows rapid stowage of windbreakers or rain shells as weather changes. A mesh vented back panel effectively reduces sweat buildup and promotes airflow, keeping you cool and dry during high-intensity efforts. The two-stage flask cinch system lets you secure bottles when full (stage 1) and tighten the pocket to prevent bouncing when water levels drop (stage 2)—all with one hand. Ergonomic design conforms to your body for a stable, bounce-free fit across various torso shapes. Premium cold-resistant hardware from NIFCO, DURAFLEX, and WOOJIN ensures reliable performance in low temperatures. Reflective details enhance low-light visibility for dawn or dusk runs, and an included mesh trash pouch promotes leave-no-trace ethics. Perfect for ultra-running, mountain racing, fastpacking, and high-intensity trail adventures.