Quick Question on Magnetic mesh screen filter

[Happy Hopping]

https://mnpctech.com/pc-computer-co...c-case-filter-magnetic-mesh-screen-small.html

I never own 1 of these before. Is the edge magnetic or is the whole thing magnetic?

and from that link, you guys think those mesh holes are small enough?

 

[ChoGGi]

"It has flexible magnetic frame"
"PVC filter material"

seems like just the edges, and going by this image looks like the designers envisioned some mighty large dust particles...

These guys make filters for popular cases https://www.demcifilter.com/products

 

[Happy Hopping]

must be anticipating cat hair