Ultraspire Soft Flask WMX Locking Cap (800ml)

Drink more for long stretches on the road. This large soft flask is intended for trail runs and ultras where you run for extended periods without a water station or aid station.

Flexible despite the larger capacity. The slim shape slides more easily into a suitable hydration compartment, and the flask shrinks as you drink. You notice the advantage especially later in a long ultra, when you don't have to refill as often.

Choose this one if reach is more important than compactness. The wide opening helps with quick filling of water, sports drink, or ice, while the lockable drinking spout limits leakage during transport.

For short runs or small jacket pockets, a more compact soft flask is more practical.