Completely collapsible for superior packing efficiency, our burliest medium-to-large capacity water storage and delivery systems are perfect for everything from alpine- to road warrior-style expeditions. Armed with incredibly tough 1,000-Denier exteriors and now laminated with an improved BPA-free food-grade lining for better-tasting water, these bags can handle freezing and the abuse inflicted by expedition crews and hardcore adventurers. MSR's Hydration Kit accessory adds do-all versatility, and the new svelte 3-in-1 cap lets you fill, drink and pour with greater ease.