Sea to Summit eVent Compression Dry SackSmall - Grey Sea to Summit eVent Compression Dry Sack - in stock now. A Backpacker Magazine Editor?s Choice Award Winner, say hello to the Sea to Summit eVent Compression Dry Sack. Sea to Summit were the first to introduce a compression dry bag which does not use a purge valve. This innovation Uses air permeable eVent fabric on the base, which allows air to be pushed out of the sack, but water can?t get in. This is a lighter, simpler and more reliable solution than a purge valve. The body is made of a tough 70 D polyurethane-coated fabric. It has a Hypalon roll-top closure like Sea to Summit Dry Sacks and a lid with four straps for even compression. Products on Sale Are Discontinued Styles or Colors. Features of the Sea to Summit eVent Compression Dry Sack Unique compression idea - allows air to be pushed out to compress, but water can't get in because of the waterproof, air permeable eVent fabric base Waterproof seams - double stitched and tape sealed Roll top Hypalon; closure with lid and 4 straps evenly compresses and maintains compressed size Reinforced stitching on all stress points Pull handle on the bottom Super compact and very light Avoid contact with sharp objects or subjecting the sack to High abrasion, as this could compromise the waterproof fabric.