K12 micra pollen filter

Hi all,
I am the happy owner of a K12 micra 1.5 dci without Air conditioning (year 2004).
I decided it would be a good idea to swap the pollen filter over the holidays.
After removing the glove box and looking in the expected location, all I could find was a sealed housing which was impossible to open (according to other threads it should be a lot easier).
See below picture for what I found:


Does this look like a pollen filter or could it be just a sealed empty housing? Maybe pollen filters are only fitted on certain K12 Micras (with Air conditioning only)?
Thanks in advance for any replies that could help clarify this.