18oz Insulated Soft Flask with ExoSpine

Built for runners and endurance athletes who need cold fluids on long efforts, this is our pick for hot-weather hydration. Double-wall insulation keeps drinks cold twice as long as standard flasks, while the rigid ExoSpine holds its shape as the fluid level drops — no collapse, no awkward sloshing.

• Double-wall insulation keeps liquids cold up to twice as long as uninsulated flasks and eliminates exterior condensation sweat on your hands or gear
• Rigid ExoSpine™ internal structure maintains the flask's shape as it empties — no collapsing, no fumbling mid-run
• High-flow silicone bite valve delivers a fast, clean pull and self-seals after every sip to prevent drips in your vest pocket
• Slim, flexible TPU body compresses as you drink to reduce liquid movement and fits standard running vest pockets, waist belts, and handheld sleeves
• Wide-mouth opening fits ice cubes and makes filling and cleaning straightforward — 100% BPA-free, PVC-free, and taste-free