The Narrow Mouth Tritan 500ml from Nalgene is a solid water bottle built from tough durable Tritan plastic with a no-leak lid which offers peace of mind that your water will still stay where it belongs & not all over your gear when out exploring. It features a Narrow Mouth opening so less water rushes out while you drink, leaving you to enjoy the view. If water is all you are looking to have in your water bottle, this is the ideal bottle for you.