Sleek, insulated design fits perfectly under your ski parka for comfortable winter hydration on-the-go!. Ergonomic design won't interfere on the ski lift, and allows you to move freely while you shred the slopes. Over-the-shoulder tube routing puts water right where you want it. Tube and Big Bite™ valve are insulated to keep liquids from freezing. Closed-cell foam keeps liquids colder longer, and won't absorb perspiration. Abrasion-resistant, lightweight and durable shell protects the reservoir. Flexible reservoir delivers tremendous burst strength and is able to handle temperature extremes. Leak-proof, screw-cap closure makes reservoir easy to fill, and is large enough for adding ice cubes.