The blue, 5L Waterproof Dry Tube Bag from OverBoard is used to protect equipment and gear, such as a digital camera or other small valuables, against the elements. It is a 100% waterproof 600 denier 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 is carried by the adjustable, removable shoulder strap or the top carry handle.