Before starting with my question, I would like to introduce myself. As Walter has already noticed (thank you for the friendly welcome

My name is Joachim, I'm a software engineer living near Stuttgart, Germany. My solar equipment are two H-Alpha scopes (Solarmax II 90, Solarmax II 60) and some Baader white light filters. Although I like visual observation, my latest toy is the ASI174.
Now to my question: Yesterday I received and installed a MoonLite focuser for my Solarmax II 90 (report will follow). According to the detailed description, I should unthread a filter lens from the focuser's drawtube and install it in the provided MoonLite adapter (see pictures from the installation manual).
But inside my helical focuser there isn't anything like a filter. There is nothing (besides tube parts) between OTA and blocking filter, the silvery part on the pictures is missing. Here is the picture of my disassembled focuser:
What kind of filter should it be? Is it really missing or was there a design change?
Thanks in advance,
Joachim