Ultraspire x UltraFlask 550 Hybrid Running Water Bottle - Ultra Squeezable, Soft and Comfortable, BPA and PVC Free, Made in The USA

I own two of these flasks and use them all the time. they work well for me for running, travel, and camping as they are seriously lightweight and the perfect shape, and fit perfectly in other Ultraspire products. However, I do have to say they are not always the most secure bottles as there are some issues with the rubber nozzle. If not pressed down all the way the nozzle can let water through, also over time the rubber mouthpiece can become slightly misshapen allowing water to very slowly drip out if not kept verticle. If you can deal with some minor leaking from time to time the tradeoff is worth it.

Cap does not seal well to the bottle so it leaks whenever I have it in a horizontal position a lot. Using the cap from a different flask that fits the bottle and is better designed.

When this bottle arrived, it smelled like Costco, which is odd. (What is that smell? Pallets? Boxes? Plastic?) The smell went away in a couple of days, fortunately. This is absolutely my favorite reusable bottle: the flask shape means it doesn't fall out of my jacket or side pocket of backpack, I don't have to worry about accidentally dropping and breaking it, I can squeeze it so that when I'm running or hiking the water ends up in my mouth and not all over my face, and it doesn't impart a plastic taste or smell to the water. Also, I like the fact that it comes in lime green.

I bought this thinking it was designed for my Zygos 4 vest, but either I'm wrong or the bottle is poorly designed. bulky in the vest, and just too big. I also don't like the valve much - I don't want to have to pull to open, but would rather use a bite valve. I'll return and stick with my soft flasks.

Doesn't leak or drip -- sorta important, don't you think? And yet many water flasks I've bought do, and much more expensive ones! So that's good. As well, the bottle is soft enough that it conforms nicely in a chest-pocket style vest, which means less rubbing or bruising, AND easy to squeeze to get water out at higher volume that other flasks I've used.

These water bottles work perfectly with the running vest my wife got for Christmas. I was green with envy upon seeing them. They surprisingly hold a decent amount of H2O, and are ok to clean.

Ordered as an additional bottle for longer runs. The Ultraspire Momentum vest and bottles are a great combination.

Perfect balance of firmness and squish. Do wish another style of cap was available, but this works.

Ottima borraccia, compatibile con gli zaini Ultraspire. Nonostante non sia un modello "softflask" , risulta comunque molto morbida e la particolare forma si adatta perfettamente oltre che alla tasca dell zaino anche alla fisionomia di chi lo indossa.Per correttezza devo dire che sto sperimentando delle softflask di una catena di negozi sportivi che si adattano perfettamente anche loro alle tasche degli zaini Ultraspire.