UltrAspire 1 Litre Soft Flask with Locking Cap

• 1 litre capacity: provides greater fluid capacity when longer gaps between refills or additional hydration are expected.
• More durable construction: slightly thicker material supports the larger fluid volume while providing increased resistance to punctures.
• Defined bottle shape: straighter, more parallel sides and a flatter base help the larger flask retain a practical shape when filled.
• Locking 42mm cap: helps prevent accidental leaks or spills while being carried.
• 42mm wide opening: makes refilling easier and provides room for adding carbohydrate or electrolyte powder and ice.
• Collapsible body: allows air to be expelled to help reduce sloshing and compresses as fluid is consumed.
• 42mm accessory compatibility: accepts the UltrAspire Bloddle Hose Attachment and Soft Flask Straw with 42mm Cap for alternative drinking setups.
• Pack compatibility: designed to fit the side pockets of the UltrAspire Traverse and Purist packs.
• HydraPak collaboration: developed by UltrAspire in collaboration with HydraPak.
• PVC and BPA free.

The 42mm opening is compatible with the UltrAspire Bloddle Hose Attachment and Soft Flask Straw with 42mm Cap. The Bloddle allows the 1 litre flask to be used as a larger remote-drinking reservoir when carried in a suitable waist pack or backpack, while the straw provides easier access when the flask is positioned within reach.

The flask is designed to fit the side pockets of the UltrAspire Traverse and Purist packs.

Because of its 1 litre capacity and larger dimensions, fit with other carrying systems should be checked against the available pocket size and retention system rather than relying on nominal 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, capacity or whether this product is suitable for what you need, get in touch for straightforward advice.