Concur with Patowalker. I actually passed the Belgian ULM test in an FK9 - mixed memories there, but mostly sweet.
Like many planes of its class - i.e. 2 seater 80 hp-Rotax powered - the FK9 has a demonstrated max gross of 540-560 klg, but its makers and/or importers preferred to certify it as microlight/ULM with a max up of 450 kg, later increased to 472,5 kg to allow for a BRS, as is mandatory in Germany.
We ought really to get out of this confusion with a workable Euro-wide LSA definition.