The blue 40L OverBoard Waterproof Dry Tube Bag is used to protect equipment and gear, such as a digital camera or other small valuables, against the elements. It is a 100% waterproof, 600D PVC Tarpaulin roll-top dry bag with an OverBoard Fold Seal System. Roll up the neck tightly 3-4 times to expel all the air and then connect with the plastic snap couplers. When closed, the couplers can also be used as a handle. The bag will float in the water when properly sealed. It is carried by the heavy-duty grab handle and the adjustable, removable shoulder strap.