Easy Sipper Though the wide mouth of the classic 32 oz. Nalgene water bottle is convenient for filling and cleaning the bottle, it isn't always the ideal opening for easy and spill-less drinking. Fitting snugly into the opening of 32 oz. wide mouth Nalgene water bottles (not compatible with other types of Nalgene bottles), the Nalgene Easy Sipper solves the problem by narrowing the flow of your water or other beverage. The Easy Sipper pops out easily, allowing for the same easy filling and cleaning features to which you've become accustomed. Sold individually, the dishwasher-safe Nalgene Easy Sipper is available in your choice of colors.