The CamelBak Trail Run Vest is a great fit for all levels of expertise, from entry-level athletes to elite trail runners. This vest includes two Quick Stow Flasks 500ml in the front for easy-to-reach hydration. A sleek, lightweight design makes this vest versatile for half marathon to marathon distances while an adjustable fit around the sides and sternum allow you to personalize the fit to your body. In addition, padded 3D vent mesh back and straps keep you dry and comfortable so you can focus on the trail ahead.