This slim-fit running vest is designed for runners with a 29 to 37 inch chest who want just enough hydration for 5K, 10K, half marathon, and marathon distances without the bulk of a full hydration backpack. Weighing only 7.16 ounces, it stays invisible during summer morning runs and hot weather training. The included 500ml soft flask sits in a front chest pocket for easy sipping — no bladder, no hose, no tube. Ten pockets hold phone, gels, keys, and snacks within reach while running. Breathable 3D air mesh and adjustable dual sternum straps keep the vest locked in place with zero bounce, even at tempo pace. Built specifically for slim and petite runners who find standard hydration packs too large, too heavy, or too bouncy. Reflective accents provide visibility for pre-dawn and after-dark runs. Perfect as a race day vest or daily training companion for runners upgrading from a handheld bottle or armband.