Filter-Compatible Flasks

Part of our ultra-light series, the 500 ml is so light, you might forget you brought it. Weighing in at just over an ounce, it’s optimal hydration, no matter what kind of runner you are. Its pliable material conforms to most pockets, it shrinks as you drink to minimize water movement and it can be used with or without the tube. Topped with a new feature, the SpeedFill™ cap, makes aid station refills a breeze. Ultra light weight, ultra useful.

Go big. The largest of our ultra-light series, the UltraFlask Speed 600 ml holds more so you can go the distance. Its soft material allows it to fit snugly in most vest pockets and it shrinks as you drink to minimize water movement. Topped with our newest SpeedFill™ cap feature that makes aid station refills a breeze. 

Go big. The largest of our ultra-light series, the UltraFlask Speed 600 ml holds more so you can go the distance. Its soft material allows it to fit snugly in most vest pockets and it shrinks as you drink to minimize water movement. Topped with our newest SpeedFill™ cap feature that makes aid station refills a breeze. 

Keep your water cool and prevent bottle sweat. An insulated version of our handheld SkyFlask™ Speed 350ml soft bottle, the SkyFlask IT Speed 350ml features our IsoBound™ technology. Engineered to keep fluids at an ideal temperature 38% longer than a standard flask.

Take matters into your own hands with the SkyFlask™ 500ml handheld. Designed for the minimalist runner, the SkyFlask is lightweight and easy to hold with an adjustable hand strap for a more precise fit. It has a twist locking cap, high-flow bite valve, and large opening for rapid refills. Your next PR awaits.

Keep your water cool and prevent bottle sweat. An insulated version of our handheld SkyFlask™ 500ml soft bottle, the SkyFlask IT 500ml features our IsoBound™ technology. Engineered to keep fluids at an ideal temperature 38% longer than a standard flask.