Custom-Built Soft Flask (250ml / 9oz) brings the same proven Endorphin hydration system in a lighter, everyday size. Built for the runs where you want water on hand without carrying more than the run requires. Collapsible Design: This flexible flask shrinks as you drink, minimizing sloshing and staying quiet and stable as your run progresses. High-Flow Bite Valve: The same leak-resistant, self-sealing nozzle as the original Endorphin Soft Flask for quick sips without spillage. Durable & Safe Materials: Made from BPA-free, odor-resistant materials that withstand frequent use and multiple refills. Modular Carry: Sized to fit the front pocket or rear compartment of the Endorphin Belt. Run it solo for everyday miles, run two for balanced carry, or pair it with the 450ml flask for up to 700ml of total hands-free hydration. Features: 250 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: black with white logo Weight: 29g