💦 Hydrate smarter, run farther — the flask that keeps up with your hustle.
The Ultraspire SoftFlask is a 500ml ultralight, BPA & PVC-free silicone hydration flask designed for trail and distance runners. Its collapsible shape fits hydration vests effortlessly, featuring a wide top for ice cubes and a silicone Phaser bite valve for spill-resistant, clean-tasting hydration. Durable, comfortable, and toxin-free, it’s the perfect companion for serious athletes who demand convenience and performance.
| Brand | Ultraspire |
| Material | Silicone |
| Color | White |
| Capacity | 500 Milliliters |
| Special Feature | Straw,Valve |
| Age Range (Description) | Adult |
| Product Dimensions | 5"W x 3"H |
| Product Care Instructions | Hand Wash Only |
| Model Name | Softflask |
| Recommended Uses For Product | Trail |
| Number of Items | 1 |
| Reusability | Reusable |
| Shape | Round |
| Material Type Free | BPA Free, PVC Free |
| Style | w/Straw & Bite Valve |
| Finish Type | Glossy |
| Sport | Running |
| Unit Count | 1.0 Count |
| Manufacturer | UltrAspire |
| UPC | 747531034806 |
| Item Package Dimensions L x W x H | 13.15 x 3.78 x 2.32 inches |
| Package Weight | 0.05 Kilograms |
| Item Dimensions LxWxH | 5 x 5 x 3 inches |
| Brand Name | Ultraspire |
| Suggested Users | unisex-adult |
| Part Number | UA034STW |
| Included Components | item |
| Size | 16.9 Ounces |
M**K
Keeping Me Fueled
I bought this as I was training for a 50K ultramarathon. I had already bought an ultraspire vest in the past, so I wanted to make sure that what I ordered would actually be sized right and work with the vest. I had the hard plastic bottle, but didn't like the sloshing, and that's what led me to the flask.This flask fits perfectly in my vest, and after a few sips, the vacuum created causes the flask to collapse, and gets rid of the sloshing factor. Works well with my electrolyte mixes as well.My one concern is that the flask feels a little thinner than other types of flasks that I own (the GU flask for example). So far I have had zero issues and have actually ordered a second flask so that I can have one with water and one with electrolyte during races.
T**A
No protective cap
This is fantastic with only 1 big flaw... No protection cap for mouth piece.This limits the use options dramatically.I end up having to use baggies to carry it or to send in my son's backpack.While it doesn't leak, the mouth piece gets dirty quickly due to exposure, be it dirt, sprays etcHave to be very mindful when using it for anything other than immediate complete use before cleaning time.Other than that? It is wonderful.
A**Z
Durable
Just came from competing at an ultra marathon through the Sahara desert and these bottles saved me. Easy to use, durable and convenient.
U**1
Best solution for hydration vests
Used this bottle with maurten 320 in the front pocket of a nathan hydration vest for an ultra to allow for water and maurten to be carried. Didnt leak, worked as advertised, fit great in the pocket.
S**E
Great for running
Fits in your pocket after use
T**7
Leaking
Starting leaking at seam after 3 uses.
K**R
Chemical Water
Chemical water :/ I purchased this soft flask so I could bring along a little extra water on my longer runs (15mi. +/-). Today @ about mile 12 I ran out of water in my handheld and sipped off this soft flask, it tasted terrible and w/in a mile I was on the side of the road feeling sick to my stomach. I dry heaved approx 5 times and the last I vomited bile. Designed in USA, made in China. No thanks.
D**7
Is not what I was expecting.
Is not was what I was expecting, the straw won’t go down it’s permanently out. It gets on your way when you are running especially if you use it on vest.
Trustpilot
4 days ago
3 days ago
