The roll-top seal ensures reliable watertightness, convenient and practical. You simply open the bag to let in as much air as possible, then roll the top down 3 to 5 times and clip the ends together. This keeps air in bag, prevents water from seeping in and allows bag to float. As long as the bag is not completely submerged, whether in rapids or other wet situations, it flawlessly keeps the contents dry, protecting them from water, snow and sand. Keep your items and valuables dry when you do some water sports like boating and kayaking, camping, beaching. Transparent dry bag, easy to find your items without trouble, you don’t have to rummage through the bag to find your things. It is made of 0.5mm PVC that is resistant to wear, tear and remains flexible all year round. The seams are expertly welded and reinforced, strong and reliable. Heavy duty buckles, dense straps, secure stitching all enhance the bag’s overall strength. It won't wear easily in harsh conditions.