If there's one thing we know best, it's water. Our athletes, customers and colleagues told us they wanted a reservoir that delivered more water per sip, with a foolproof design that made it easy to fill up and hit the trail. Crux delivers 20% more water per sip, with an ergonomic handle for easier refilling, and an on/off lever that makes it easy to prevent leaks. Like all of our gear, we put the Crux through exhaustive stress tests to make sure that it won't fail you on the trail. 100% free of BPA, BPS and BPF.