The Nalgene Flask is leak proof and it&';s slender profile makes it less bulky. Wherever you&';re going and whatever you&';re drinking, take along a Nalgene flask. Features and one-ounce, shot glass cap, and fits easily into bags and packs. Includes a durable insulation sleeve. Suitable for long-term beverage storage. Prevents plastic odor and taste. Volume: 10 ounces (300 ml).