The seal line discovery view 20l dry bag ultra durable dry protection with easy viewing save time and energy by swiftly identifying contents in our waterproof discovery view dry bag the purgeairtrade valve quickly vents trapped air for easy closing and packing while the oval bottom helps keep the bag from rolling around seal line discovery view 20l dry bag features purgeairtrade equipped new waterproof valve helps the bag compress further once itrsquos been se