One of the major concerns in Survival is water. One of the drawbacks of storing water in a Survival Pack is containment. Store purchased bottled water is filled too a point that if the water freezes, it will pop the cap off or even burst the bottle open. Not a good thing to find out when you need it, or find out that your other gear is not only soaked, but moldy and mildewed from the moisture. U.S. Coast Guard approved sealed drinking water bags is a stable substitute until you can obtain drinkable water in an emergency situation. The bag in the picture has been in my deep freeze for over a month. No leaks. No busted seams due to expansion of the water into ice. Shelf Life for this type of water is 5 years. MFG date & Exp Date is stamped on the back of the bag. Each bag of this size contains 4.227 Fluid Ounces. Physical weight is 4.5 ounces on my wife's kitchen dietary scales. I would say that a few of these water bags would be a worthwhile addition to any Survival kit as a support or adjunct, to whatever other type of water program you have planned for. If frozen, you can put under your outer coat, (never against skin), and allow it to thaw from body heat. This is much like medics that carried plasma under their coats in WWII to prevent freezing.