The perfect balance of sleek and stable, our signature UltraFlask has a wider form and a durable 3D welded bottom. Soft and pliable material means you can fit it in most pack and larger vest pockets for a snug and secure fit. Topped with our SpeedFill™ Cap for quick refills.

Vest Pack Fit — Soft material conforms to most hydration packs and larger vest pockets for a secure and stable fit.

High-Flow — Easy to drink bite valve auto-seals after each sip, eliminating annoying drips.

Speedfill Cap — Designed for fast filling - flips open for quick refills and snaps closed for leakproof transport.

Large Opening — 42mm opening lets you fill the flask easily with ice and drink mixes.

Compressible — Flexible design shrinks as you drink, reducing water movement.

Filter Compatible — Pair with 42mm threaded backcountry water filters including the HydraPak 42mm Filter Cap.

Durable — Made of ultra-durable, abrasion resistant TPU & RF welded seams for superior durability and elasticity.

100% BPA & PVC Free — Wide working temperature range (can be frozen - max temp 60° C / 140° F).

• Highlights: Fits Running Packs & Vests | Lightweight TPU | Packs Down | Speedfill Cap.