Key Features:

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.
Breathable air mesh back panel for a lightweight, comfortable fit.
Reflective accents for visibility in low-light environments.
Stretch overflow storage compartment lets you easily stash a rain shell or extra layer.
Safety whistle built into sternum strap.