Crux reservoir the brand new crux delivers 20 more water per sip with an ergonomic handle for easier refilling and an onoff lever that makes it easy to prevent leaks offers 20 more water per sip leak proof cap is easier to open and close onoff lever lets you seal your drinking tube shut with one hand hydroguard technology inhibits the growth of bacteria in the reservoir and tube big bite valve self seals after each drink eliminating annoying drips