Thanks to the smaller opening of the Narrow Mouth less water can rush out, making it easier to chug mindlessly. For Your Everyday Adventures! Take your Nalgene bottle to the gym, office, camping, exploring and everywhere in between. This Nalgene water bottle is completely leak proof, made of virtually indestructible BPA-free Tritan, easy to clean and dishwasher safe on the top rack. Free of BPA, BPS and phthalates; marked with milliliters and ounces for easy measurement. Whether you're looking for a virtually indestructible water bottle for a backcountry adventure, or you want a clean, green way of storing your dry pasta, you'll find a Nalgene product that gets the job done.