The MSR® DromLite™ 4-Litre Water Storage Bag offers high-capacity water storage yet collapse all the way down to the size of its cap. This supreme packability comes with the weight savings to match to keep you moving quickly on the trail. It is constructed of a rugged film and RF-welded seams, which offers reliable durability. Inside, an improved BPA-free food-grade lining ensures better-tasting water and can handle freezing. The svelte three-in-one cap lets you fill, drink and pour with ease.