Home > Bottles / Soft Flasks > UltrAspire >

New! 

UltrAspire Ultraflask 550 Hybrid Soft Bottle
UltrAspire Ultraflask 550 Hybrid Soft Bottle
 
Price: £10.75
Order by 2pm Monday–Friday for same-day dispatch. Delivery & Returns • Contact Us

Colour




Quantity:
Description
 
UltrAspire UltraFlask 550 Hybrid Bottle
550ml · Semi-rigid hybrid · ~71g

A 550ml hybrid running bottle combining the squeezability and body-hugging shape of a soft flask with enough structure to hold its shape. The semi-rigid construction makes it easier to grab, remove and return to a compatible vest or waist-pack pocket, including as the bottle empties.

The UltraFlask stands upright on its own, making it convenient to fill or place on an aid-station table, while its soft, curved body sits flatter against the body than a conventional hard bottle. A high-flow push/pull valve provides simple drinking and the large opening accommodates ice cubes.

Features
  • Semi-rigid hybrid construction: combines the squeezability of a soft flask with enough structure to retain its shape for easier handling and pocket reinsertion.
  • 550ml capacity: slightly more fluid capacity than a standard 500ml flask.
  • Stands upright: useful when filling the bottle or placing it on an aid-station table.
  • Soft, curved body: designed to sit close and stable against the body.
  • Highly squeezable: flexible LDPE body allows fluid to be squeezed through the valve.
  • High-flow push/pull valve: simple sport-bottle-style drinking mechanism.
  • Large opening: makes filling easier and provides room for adding ice.
  • Food-grade LDPE: flexible bottle construction.
  • BPA free.
Specifications
Capacity: 550ml / 18.6 fl oz
Weight: ~71g / 2.5oz
Dimensions: 21 × 9.5 × 5cm / 8.25 × 3.75 × 2in
Construction: Semi-rigid hybrid
Material: Food-grade LDPE
Valve: Push/pull
BPA free: Yes
Made in: USA
Use & Care

The UltraFlask 550 is particularly useful where the structure of a conventional bottle is helpful but a softer, more body-conforming bottle is preferred. Unlike a fully collapsible soft flask, it retains enough shape to make removing and returning it to a compatible vest or waist-pack pocket easier as the bottle empties.

Hand wash the bottle. Dishwasher use is not recommended because of its highly squeezable construction.

Need help choosing?

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.


Average Rating: Average Rating: 4.5 of 5 4.5 of 5 Total Reviews: 16 Write a review »

  0 of 0 people found the following review helpful:
 
5 of 5 Seems good Tuesday, June 30, 2026
Reviewer: Caroline  
Haven’t used it running yet

Was this helpful?

  0 of 0 people found the following review helpful:
 
2 of 5 Good idea, leaky valves Wednesday, January 8, 2025
Reviewer: Simon Willatts from UK  
I received 2 of these bottles with my Speedgoat bum bag. The bottles do a good job of being pliable enough to be easy to use, but stiff enough to hold shape and make pushing back into the bag pouches easy, plus standing upright by themselves.
The bottle valves are disappointing though. Whether through design or control of tolerances, mine leak: with a full bottle held in the orientation of the Speedgoat pouches and without pressure on the bottles, I get a wet back until I've drunk sufficient to lower the fill level.

If the valves were better, these would be ideal bottles. Bite valves made to a specification  which prevents leakage are available fro mother manufacturers, and it's a shame the Ultraspire ones haven't equalled them.

Was this helpful?

  0 of 0 people found the following review helpful:
 
5 of 5 Fantastic little bottles Sunday, October 27, 2024
Reviewer: Ryan Gregory from Brighton, East Sussex United Kingdom  
I don't get on with soft flasks at all. These are the perfect alternative. They don't stink or taint your water. They stand up on a surface.

Was this helpful?

  0 of 0 people found the following review helpful:
 
5 of 5 Superb Thursday, October 10, 2024
Reviewer: Suzanne Tanswell from London, UK United Kingdom  
Just the shape and the size that I wanted. Very high quality, too.

Was this helpful?

  0 of 0 people found the following review helpful:
 
3 of 5 Bottle honest review Monday, September 23, 2024
Reviewer: Anthony Parkin from Durham, England United Kingdom  
Works in belt, however shape does not allow for carrying a spare.
On a long round or FKT it could be a problem.
Redesign please to fit with standard flask type, so that spare can be carried by support runners.

Was this helpful?

View All Customer Reviews

Related categories:

Bottles / Soft Flasks > UltrAspire
Bottles / Soft Flasks