UltrAspire 300ml Soft Flask

• 300ml capacity: compact hydration for smaller pockets or where less fluid needs to be carried.
• 28mm opening: provides a lower-profile cap that helps the flask sit closer against the body.
• Soft collapsible body: compresses as fluid is consumed, helping reduce movement and sloshing.
• Slim, contoured shape: designed to slide easily into hydration and clothing pockets.
• Silicone bite valve: provides direct drinking from the flask.
• HydraPak collaboration: developed by UltrAspire in collaboration with HydraPak.
• PVC and BPA free.

The compact 300ml capacity and 28mm cap make this a useful option for smaller hydration and clothing pockets where a larger flask is unnecessary or less convenient.

Flask fit in running vests, waist packs and clothing pockets 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 fit or whether this product is suitable for what you need, get in touch for straightforward advice.