Thanks to the smaller opening of the Narrow Mouth less water canrush out, making it easier to chug mindlessly. Everything elseabout the Narrow Mouth is like its Wide Mouth compatriot, so youget all the durability and no-leak peace of mind but without thestress of a mess. Just note that no ice cubes or lemon wedges aregetting in here, so if you prefer more than water in your waterbottle, check out our Wide Mouth bottles.