EVERLIT Non-Vented Compact Chest Seal is created to treat tension pneumothorax, the second leading cause of preventable death on the battlefield. It is durable with an aggressive adhesive, easy to use, and performs in a wide range of operational environments. Non-Vented Shape: Oval Shelf Life: 5 Years Coverage Area: 6" x 6" Sealing the open chest wound prevents lung collapsing caused by entry/exit or multiple penetrating injuries to the chest.