Introducing the Nalgene Flask. Whether you keep it in your pocket, your purse or your pack, it stays neatly tucked away when not in use. Nalgene ingenuity makes it leakproof; a slender profile makes it bulkproof. Wherever you're going & whatever you're drinking, take along a Nalgene flask. Contains 12 ounces (350 ml) & features a one-ounce cap & durable insulation sleeve. Flask weighs 122g, if you take off the sleeve & the shot cap the weight drops to 53g.