One-liter machine is aimed at the user is the general family health care use, this kind of user itself is because of the lack of oxygen caused by the body uncomfortable, as long as in the daily life to improve the concentration of oxygen in the breathing can be improved, so in the use of the oxygen machine for the use of the need is not special.
The two-liter machine is aimed at users with less severe pathologic hypoxia, and generally this group of people has certain requirements for the oxygen concentration and stability of the oxygen concentrator, but the oxygen inhalation oxygen therapy is designed to play an auxiliary role, so there is no need for uninterrupted 24-hour inhalation of oxygen every day.
The three-liter machine is aimed at some of the more serious conditions need uninterrupted oxygen therapy crowd, this machine can support 24 hours of uninterrupted work, but also has the power failure alarm function.
So in the choice of the machine, not simply from the brand point of view of the machine to consider. Now online better oxygen elf oxygen generator is better, many people in the choice after the evaluation is also good, so you can go to more reference reference.