A single reusable pollen filter for the Philips Respironics DreamStation 2 series of CPAP machines. The pollen filter is the filter with the gray plastic frame. (The disposable ultra-fine filter for the DreamStation 2 has a blue plastic frame.)
The brand of filter you receive may be Philips or it may be a third-party filter manufacturer, depending upon availability from Philips.
The DreamStation 2 was initially released in Spring 2021.