Oxygen supply equipment is used to provide oxygen to individuals who have difficulty breathing. This equipment includes oxygen tanks, oxygen concentrators, nasal cannulas, and oxygen masks. Oxygen tanks are large, pressurized tanks that contain oxygen gas and are used to supply oxygen to individuals. Oxygen concentrators are machines that filter oxygen from the air and deliver it to individuals. Nasal cannulas are small plastic tubes that are inserted into the nostrils and used to deliver oxygen to individuals. Oxygen masks are devices that cover the nose and mouth and are used to provide oxygen to individuals.