Designed with input from celebrated ultra runner Zach Miller, the sleek Nathan VaporZach 2.5L race vest offers a close, chafe-free fit and incorporates two 12 ounce soft flasks with extended drinking tubes for effective race day hydration. Lightweight, highly-ventilated and moisture-wicking fabrication hugs your body to ensure a movement-mirroring fit and a bounce-free carry. Dual sliding sternum straps let you dial in fit without getting in the way or causing undue pressure. Innovative ExoShot Flasks ride up front in dedicated stretch harness pockets. Extended drinking tubes allow you to access water without ever having to remove the flasks from the pockets. Integrated “spines” give the flasks just enough structural support to hold their shape without being overly rigid or adding excess weight. Locking caps and bite valves ensure leak-proof performance and a high flow rate. The simple elastic design of the harness pockets does make the flasks easy to remove and put back into the pockets for refills and cleaning at the end of your run. Stretch lateral pockets and a rear main pocket combine to offer 153 cubic inches of streamlined storage. Small stretch stash pockets on the harness and a lower zippered back pocket provide additional options for stowing gels, electrolytes, a cellphone, or other essentials. Reflective hits increase low-light visibility. The Nathan VaporZach 2.5L running vest is available in your choice of sizes to guarantee a custom fit. The Small best fits 33'-35' chest sizes, the Medium best fits 36'-38', the Large best fits 39'-41', and the Xlarge best fits 42'-44'.