UltrAspire 500ml Soft Flask

• 500ml capacity: a common front-vest hydration size and useful as one half of a two-flask 1 litre setup.
• 42mm wide opening: makes aid-station refilling easier and provides room for adding carbohydrate or electrolyte powder and ice.
• Soft collapsible body: compresses as fluid is consumed, helping reduce movement and sloshing.
• Slim, contoured shape: designed to slide into hydration pockets and sit close to the body.
• Silicone bite valve: provides direct drinking from the flask.
• HydraPak collaboration: developed by UltrAspire in collaboration with HydraPak.
• PVC and BPA free.
• 42mm accessory compatibility: compatible with the UltrAspire SoftFlask Straw with 42mm Cap, Bloddle Hose Attachment and HydraPak 42mm Filter Cap.

The 42mm opening accepts compatible UltrAspire 42mm hydration accessories, including the Soft Flask Straw and Bloddle Hose Attachment, as well as the HydraPak 42mm Filter Cap.

Flask fit in running vests and packs depends on the available pocket dimensions and retention system, rather than capacity alone.

Not sure which bottle or soft flask is right for your vest and hydration setup? See our Running Bottles & Soft Flasks Guide.

For help comparing the UltrAspire range, see our UltrAspire Bottle Guide.

If you are unsure about compatibility or whether this product is suitable for what you need, get in touch for straightforward advice.