Well...it's a filter. Hopefully it does what it says. The only thing I didn't like about it was that it was blue, which doesn't look that great (my previous one was a more subtle gray). On the plus side, it might be easier to tell if it's dirty, but why can't they just be white???
Turned out to be just enough smaller than the 3M ones that they fall out of the filter frame. I'm going to have to shim them out with foam tape. Also, a lot less filter material in them than the 3M. Fewer pleats. Got what I paid for, I guess.