Go big. The largest of our ultra-light series, the UltraFlask 600 holds more so you can go the distance. Its soft material allows it to fit snugly in most vest pockets and it shrinks as you drink to minimize water movement.
Smart design, meet peak performance – also known as the Shape-Shift Reservoir. Our time-tested creation for hydration on the go, it can take a serious beating, it fits nicely in most packs and it’s fully reversible for easy cleaning.