Nalgene Grip 'n Gulp Sipper Replacement Valves -Nalgene containers have stood up to some of the worlds most extreme conditions. Small potatoes compared to small children. The new Nalgene Grip'n Gulp™ is tough enough to survive being thrown form a moving minivan, spill proof enough to compel parents to blame the rug stains on the dog, and odor proof enough to allow leftover milk to go undetected under the couch for months. Most importantly, its a great way for little kids to reach new heights. Includes 2 ValvesFits Nalgene Grip 'n GulpBPA Free