500ml Soft Flask for Running | Leak-Proof & BPA-Free

£10.50

Universal Vest Fit: Designed to fit most hydration vests and packs; perfect for marathons, trail running, and ultras.

Leak-Proof Bite Valve: Features a high-flow bite valve for effortless, hands-free sipping without the risk of spills.

Rapid Refill 42mm Cap: The wide-mouth opening makes it easy to add ice cubes or refill quickly at race aid stations.

No-Slosh Technology: The flexible, collapsible design shrinks as you drink, eliminating annoying water movement and sloshing.

Pure Taste & BPA-Free: Made from durable, taste-free, and recyclable TPU. No plastic aftertaste, just pure hydration.

Vibrant Colour Options: Available in Coral Flame, Aqua Blue, and Dark Teal to help you easily identify your water vs. electrolyte mix.

Hydration That Moves With You.

The KitFox 500ml Soft Flask is the lightweight, durable solution for runners who need reliable hydration without the bulk. Engineered for the demands of the trail, this flask collapses as you drink, eliminating the "sloshing" sound and feel of traditional bottles.

Whether you're navigating a technical mountain ultra or a humid summer road run, the high-flow bite valve ensures you get the hydration you need with zero effort. The wide 42mm opening is a game-changer for race days—allowing for lightning-fast refills and the easy addition of ice or electrolyte tablets.

Available in three fun, bold colours, these flasks don't just perform—they stand out. Match them to your kit or use different colours to distinguish between water and your fuel mix at a glance.

Capacity: 500ml (17 fl oz).
Weight: Ultra-lightweight (approx. 35g when empty).
Material: 100% BPA and PVC-free TPU; taste-free and recyclable.
Cap Size: 42mm wide-mouth opening.
Care Instructions: Top-shelf dishwasher safe. Pro Tip: Store in the freezer between runs to keep it fresh and bacteria-free!

Frequently asked questions

A running soft flask is a lightweight, flexible water bottle designed to fit easily into a hydration vest or running belt. As you drink, the soft body collapses to reduce sloshing and make running more comfortable. The KitFox Soft Water Flask is made from BPA-free TPU, so it’s durable, taste-free, and perfect for runners, hikers, and outdoor adventurers.

Yes — the KitFox Soft Water Flask is compatible with most major hydration vest brands, including Salomon. Its flexible shape and 40 mm wide neck make it easy to refill at aid stations and water taps. If you’re unsure about sizing, just drop us a message and we’ll help you find the perfect fit.

We recommend hand washing your KitFox flask with warm, soapy water after each use. To keep it fresh between runs, store it in the freezer — this helps prevent bacteria build-up and odours. Avoid using boiling water or dishwashers, as these can damage the TPU material.

Absolutely. The KitFox Soft Water Flask can safely hold water, electrolyte mixes, and sports drinks. Just rinse it thoroughly after use to prevent residue build-up or flavour transfer.

No — the leak-proof design and bite valve ensure your soft flask won’t spill in your running pack or hydration vest. Whether you’re trail running, racing, or hiking, you can stay hydrated without worrying about leaks or drips.

The KitFox Soft Water Flask has a 40 mm wide neck and a 250 mm length, making it the ideal size for most running vests and trail packs. Its flexible body means it collapses as you drink, saving space and reducing bounce.

Our KitFox Soft Flask is made from BPA-free, food-grade TPU that’s completely taste-free. If you ever notice a hint of flavour, rinse it with a little baking soda and warm water or store it in the freezer overnight — it’ll be fresh and neutral by morning.

Yes — you can partially freeze your KitFox Soft Water Flask for extra-cold hydration on hot runs. Just leave room for the water to expand and don’t fill it all the way before freezing.

Yes — it’s made from recyclable, BPA-free TPU, designed to be durable, long-lasting, and reduce waste compared to disposable bottles. It’s the perfect choice for sustainable runners and outdoor enthusiasts.

Unlike rigid running bottles, the KitFox Soft Water Flask collapses as you drink, preventing sloshing and bounce. It’s lightweight, leak-proof, and compatible with most hydration vests — making it the ultimate hydration companion for trail runners, marathoners, and hikers.

Frequently asked questions

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