The 5L oxygen concentrator is a medical grade device that can deliver supplemental oxygen to those who cannot get enough oxygen on their own. It can treat patients with COPD, pulmonary fibrosis, and other hypoxia-associated conditions efficiently and comfortably. When used alongside a BiPAP machine, the O2 concentrator will enhance the effectiveness of treatment. Patients with COPD especially benefit from the method due to better removal of excess CO2 from their bloodstream.