Dr. Oxygen is a portable oxygen generator, most efficient, economical and safe. Dr. Oxygen generates more than 12 liters of 99.8% oxygen by one time simple mixture of a couple of special powder packs and water into the portable reaction tub. There is no need using electric power or highly pressurized oxygen, because Dr. Oxygen works on the basis of a safe chemical reaction; that is, 'powder b(90g)' contains oxygen and 'powder a(5g)' controls the duration and degree of reaction as a stabilizer. The US patent (no.043487), CE, TUV, ISO and our quality control warrant this device and the special way of safe chemical reaction. Dr. Oxygen can be used by anyone who require pure oxygen. You can see the details of the product on dr-oxygen.com.