The zipper closure is the reason I bought this, and it holds up well even after being shoved in my tote all week. It folds flat enough to slip into a jacket pocket, yet stands on its own once it's open at the park.
Stella S.★★★★★
I keep this clipped to my backpack on every trip now, and the zippered design means it folds flat enough to forget it's even there. The self-supporting shape held up perfectly on gravel and mud without tipping over once.
Lily★★★★★
We took this on a weekend hike, and it stood up on its own even on uneven ground, which made filling it with water one-handed a breeze. The zippered top keeps it flat and tidy in my pack when it’s empty, and it’s so light I barely notice it’s there.