The practicality of this 1 litre Nalgene Wide Mouth bottle is enhanced by the wide neck, so that washing out or filling the bottle with ice is no problem. The design looks simple, but it's backed by over 50 years of manufacturing experience. The lenses help you keep track of your drinking regime or make it easier to mix a drink (such as an isotonic). The cap is attached securely to the bottle with a strap so you won't lose it, plus you can carry the full bottle around comfortably.