The white filter material is permanently attached to the light blue plastic filter housing. They are not designed to be detached from one another.
Ultra Fine Filters, from Philips Respironics, are an optional accessory for increased filtration efficiency, for use with all DreamStation CPAP & BiPAP machines.
USAGE: 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, slide the blue foam pollen filter out of the machine, securely snap the light blue 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.