The Nalgene Flask is leak proof and it's slenderprofile makes it less bulky. Wherever you're going and whatever you're drinking, take along a Nalgene flask. Features andone-ounce, shot glass cap, andfits easily into bags and packs. Includes a durable insulation sleeve. Suitable for long-term beverage storage. Prevents plastic odor and taste. Volume: 12 ounces (350 ml).