Nathan Soft Flask collapsible running bottle — 414 ml (14 oz) Bite Top, leak-resistant & packable

Nathan Soft Flask with Bite Top is a lightweight, 14 oz collapsible running bottle that delivers spill-resistant hydration and packs down small when empty.

Designed for runners who want an unobtrusive way to carry water on short to medium outings, this soft flask pairs a leak-resistant bite valve with a bonded internal spine so the bottle keeps its shape even as fluid levels drop. The wide mouth makes refills and cleaning straightforward, the materials are BPA- and PVC-free, and the body is compatible with most running vests and belt systems.

How does the bite top prevent leaks while I run?

The molded bite valve stays closed until you apply pressure, significantly reducing drips during movement. It opens easily when you sip and seals automatically when released, so you can hydrate without interrupting your pace.

• Soft, user-friendly bite valve avoids accidental spills
• Self-sealing design keeps water contained between sips
• No extra caps to fumble with while moving

Will this flask fit in my vest or pocket?

This 14 oz soft flask was engineered to work well with Nathan hydration vests and most other brands’ front pockets. The flexible body conforms to tight spaces and the bonded spine helps maintain a usable shape as the bottle empties.

• 14 oz (414 ml) capacity for short runs and sessions
• Bonded interior spine preserves shape for easy removal
• Collapsible design packs flat when empty for minimal bulk

How do I clean, refill, and store the flask?

The wide opening simplifies pouring, rinsing, and adding ice or electrolyte mixes. It is top-rack friendly for cleaning and can be frozen for cold drinks; avoid exceeding the stated temperature limits.

• Large mouth for fast refills and easier sanitizing
• Freezable for cold hydration on hot days
• Safe up to 140°F (60°C); rinse and air dry fully before storing

What materials and safety features does it include?

The flask is constructed from BPA- and PVC-free materials and is made by Hydrapak for Nathan, combining lightweight performance with durable, reusable design. The bonded spine adds structural support without adding weight.

• BPA- and PVC-free materials for daily use
• Reusable, foldable, and lightweight construction
• Manufactured by Hydrapak for trusted hydration technology

Who is this for: runners, trail athletes, fitness walkers, and anyone who needs a compact, spill-resistant drinking solution for outings under a few hours. If you prefer minimal weight, want easy refilling, and like to stash a bottle in a front-zip vest pocket, the Nathan 14 oz Soft Flask is a practical, travel-friendly choice.