The SeaHorse is the perfect oxygen kit for rough environments such as: dive first aid, charter boats, marine boat use, aquatic pool, industrial oil rigs, industrial mines, cruise ships, and many more applications. The SeaHorse Double features a polypropylene shell and a water tight seal keeping your supplies safe in harsh aquatic and land environments. With two Jumbo-D aluminum cylinders and approximatly 107 minutes(at 12 lpm) worth of Oxygen, the SeaHorse Double can buy you crucial time to reach the care you need.