It is constructed from waterproof, air permeable eVent fabric on the base which. Pretty much anything will be better than this. The eVent Compression Dry Sack was the inspiration for the Evac Dry Sack. The ONLY reason I am giving this a 2 star rating instead of 1 is because backpackers that use these dry bags may find them desirable because they are very light-weight. Instead of straps for compression, just roll. For whitewater or any other boating/nautical purposes, these things are absolute garbage and a huge waste of hard-earned money. We use waterproof, air permeable eVent fabric on the base for valve-free air expulsion, allowing compact packing. Full submersion with this dry bag is out of the question. Just from the relatively small amount of water that leaks into my kayak over the course of the day, whatever I put in the dry bag will either be damp or fully soaked depending on whether or not i'm lucky. This usefulness was very short-lived however, and after not even a full summer of kayaking, my "Dry Sack" already leaks like a sieve. This past Summer I received a Sea to Summit Evap Dry Sack as a gift and initially it worked pretty well despite my concerns about it being so thin. Because this vital piece of equipment is used on almost any kayaking excursion, a dry bag (or "dry sack" in this case) should be able to hold up to regular use and at least a minimal amount of abuse.
It's flexible in both senses of the word soft and pliable, as well as ideal for many different uses. Its like a compression sack, but the design allows you.
Perfect for use in sports such as kayaking and other water sports or for trips and adventures in nature. Evac Dry Sack Event waterproof dry bag, lets air through, valveless design that allows compact packaging.