How well does a Dynabreeze Filtamat filter for my ducted AC work on PM2.5?

TLDR; Not very well

My ducting uses a Dynabreeze Filtamat I got from Bunnings for $31.50. I cannot find any mention of what its rating is so I thought I would try testing it myself.

Due to the lack of bad air around I ended up doing the rissole test, so as I cooked dinner I waited until the PM10 count was over 100 and then tested the filter along with the others.

To do the test I measured the PM behind the fan and in front of the filter.

Reading behind the fan

Reading in front of the fan

And the results are

Filter Efficiency
Filter	PM2.5	Expected	PM10	Expected
DYNABREEZE	3.02%	No Idea	3.05%	No Idea
MERV 13	66.60%	67.50%	67.47%	75%
MERV 16	87.39%	95%	88.10%	95%
HEPA	97.18%	99.97%	97.56%	99.97%

The filter isn't doing my filter when it comes to small particles.