Sea To Summit eVent Compression Dry SackThe eVent Compression Dry Sack earned a Backpacker Editors' Choice Award in 2007, and there is no question that it's still a winner today. Made from a sturdy 70D Nylon waterproof fabric in the body and lid, with an eVent waterproof but air permeable base that allows air to be pushed out of the sack. No need for a purge valve, making these lighter and simpler. The four compression straps, use hypalon roll top non wicking closure. These dry sacks are