Trusted by over 10k runners
450ml / 15oz
No-slosh Design
A Better Way To Carry Water
Trusted by over 10k runners
450ml / 15oz
No-slosh Design
A Better Way To Carry Water
Soft, collapsible flask custom-built to fit securely in the Endorphin Belt for distraction-free hydration on the run.
Soft, flexible design
compresses as you drink to minimize movement and noise.
High-flow, self-sealing bite valve
delivers fast hydration without drips or leaks.
Twist-to-lock cap
adds an extra layer of security during hard efforts.
BPA-free, odor-resistant materials
built for frequent use and refills.
Shaped to fit securely in the Endorphin Belt
for stable, hands-free carrying.
Free Shipping over $60
30-Day Risk Free
No-Bounce Guarantee
"Great flask! Good enough for a few hours race! Super comfortable during runs."
Frequently Bought Together:
Endorphin Running Belt
Everyday training essentials
Performance Hat
Keeps you cool on every run
Features
Custom-Built Soft Flask (450ml / 15oz) fits securely in the Endorphin Belt, keeping you hydrated without slowing you down.
Collapsible Design: This flexible flask shrinks as you drink, minimizing sloshing and freeing up space in your belt as your run progresses.
High-Flow Bite Valve: Equipped with a leak-resistant, self-sealing nozzle that provides quick sips without spillage.
Durable & Safe Materials: Made from BPA-free, odor-resistant materials that withstand frequent use and multiple refills.
Specs
450 ml capacity
Soft and flexible
Twist-to-lock top: zero accidental leakage
Self-sealing bite nozzle: effortless drinking on-the-go
Easy-to-grip cap: simple to open, fill, and wash
Free from BPA, phthalates, and PVC
Color: light gray and transparent
Weight: 33 g
Shipping & Returns
Free shipping and returns in Continental US over $60
30 day risk free trial
Frequently Asked Questions
How do I get the water flowing?
The flask ships sealed and locked for health and safety. When you first open it, look for the arrows and “on/off” markings on the cap. Just bit the nozzle and twist the cap slightly in the “on” direction at the same time to fully open the flow! Twisting alone may not release the full amount of water.
Does it leak while running?
A self-sealing bite valve and twist-to-lock cap help prevent leaks, even during hard efforts.
Can I use electrolyte mixes in the flask?
The flask is compatible with water and electrolyte mixes, and is made from odor-resistant materials for repeated use.
How do I clean the flask?
Rinse the cap thoroughly after each use with warm, soapy water, and then let it air dry completely. The bite valve can also be cleaned gently using a small brush or Q-tip around the opening.
What’s your return policy?
We are confident you will love it, and offer a no-questions asked 30 day return policy. If you don't like it for any reason, let us know and we will work to make it right.
Designed for Runners Who Demand More
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Features
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Contact Information
The Endorphin Belt Team
Endorphin Running Company, LLC
Soft Flask
Tested. Proven.
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