PocketFlask vs SkyFlask Speed: Which Soft Flask Fits Your Run?

Quick Answer

Choose the PocketFlask 500ml if you prioritize capacity and a low-profile fit in vests or belts; choose the SkyFlask Speed 350ml if you want a dedicated handheld with a secure thumb loop for fast-paced runs.

Capacity vs. Convenience: The Core Trade-Off

The biggest difference between these two soft flasks is how you carry them. The PocketFlask 500ml is designed to slip into run belts and vest pockets, offering a larger 500ml capacity without adding bulk. Its low-profile shape and pinch-welded bottom keep it unobtrusive, making it a solid choice for runners who already wear a vest or belt.

The SkyFlask Speed 350ml, on the other hand, is built as a handheld. Its innovative thumb loop lets you hold it securely without gripping hard, which can reduce hand fatigue on longer efforts. However, its smaller 350ml capacity means you'll need to refill sooner, and it takes up one hand—a trade-off to consider if you prefer free hands during a run.

Locking Cap and Leak Prevention

Both flasks address leaks, but in different ways. The PocketFlask 500ml features a 28mm locking cap that opens and closes with a thumb, preventing leaks and drips while in motion. This is especially useful when the flask is bouncing in a vest pocket.

The SkyFlask Speed 350ml also has a secure cap design, but the main focus is on the grip and stability provided by the thumb loop. If you've had issues with caps loosening during runs, the PocketFlask's locking mechanism may be more reassuring.

Hand Fatigue and Ergonomics

Carrying a flask in your hand can cause fatigue if you're constantly squeezing. The SkyFlask Speed 350ml solves this with a soft, neoprene thumb loop that lets you relax your grip. It's also ambidextrous, so you can switch hands mid-run without missing a beat.

The PocketFlask 500ml, when used in a vest or belt, doesn't require any hand grip at all. But if you plan to carry it by hand, its lower-profile design may not offer the same ergonomic comfort as the SkyFlask Speed's dedicated handheld features.

Trade-Offs at a Glance

• Capacity: PocketFlask 500ml offers 150ml more capacity than the SkyFlask Speed 350ml, meaning fewer refills on longer runs. If you run more than 10K without support, capacity matters.
• Carry Style: PocketFlask is designed for vests/belts; SkyFlask Speed is a dedicated handheld with a thumb loop. Decide whether you want your hands free or don't mind holding a flask.
• Ergonomics: SkyFlask Speed's thumb loop reduces grip effort; PocketFlask's low-profile design avoids pokes and irritation when stowed. If you chafe easily, consider the carry method that avoids contact points.

Product Facts

• SkyFlask™ Speed 350ml: The SkyFlask Speed 350ml is a minimalist soft-flask handheld with an innovative thumb loop that allows you to hold the flask securely without wasting energy gripping or squeezing. This reduces hand fatigue and lets you maintain a relaxed grip during fast-paced runs.

  

• PocketFlask™ 500ml: The PocketFlask 500ml is the lowest profile flask, designed to slip into the snuggest run belts and leanest vest pockets, with a new 28mm locking cap that prevents leaks and drips while in motion. Its slim design and secure cap make it ideal for runners who prefer hands-free carrying in vests or belts.

  

Which Should You Choose?

Best for

• Runners who wear a vest or belt and want a larger 500ml capacity without bulk
• Trail runners who prefer hands-free carrying and need a leak-proof locking cap

Not for

• Runners who want a dedicated handheld with ergonomic grip features—choose the SkyFlask Speed instead