This is a lightly used Osprey Men’s size small Duro LT running Hydration Vest with two 12 oz water bottles. Chest size 30-35 inches (equivalent to women’s medium) Has one zip pocket on the front with whistle. Can also hold phone. Vest has two lower velcro pockets on front, one with key clip. Ideal for gels, snacks, gloves etc. There is a larger open planet on back that fits a light jacket or extra layer. All in excellent condition.