The filter on the Inogen One G4 will need to be replaced. They keep dust, pet hair, and other air-borne contaminants away from your oxygen.
The removable particle filters cover the air intake screens. They are washable and reusable, making them one of the most eco-friendly features of Inogen concentrators.
It is recommended to wash and dry the filters weekly (more often in very dusty environments) to help keep the concentrator working properly.
Filters need to be replaced when it becomes misshaped or when the screen is damaged.