This is the Replacement Cabinet Filter with Cover for the Philips Respironics EverFlo Stationary Oxygen Concentrator. The Cabinet filter is easily washable and reusable. Cabinet filters are reusable. Every filter should be washed monthly with soap and warm water. Dry the filter thoroughly before replacing it in the unit and using. These filters will deteriorate over time, so they must be visually inspected for cracks and breaks. Replacement can be from 3 months to a year.