These filters are disposable and should be replaced after 30 nights of use or sooner if they appear dirty. To install an ultra fine filter in your DreamStation 2, slide the foam pollen filter out of the machine, securely snap the ultra fine filter onto the base of the foam pollen filter, and insert them both back into the device. For complete instructions review the documentation that came with your equipment.
Note: The white filter material is permanently attached to the plastic filter housing. They are not designed to be detached from one another.