Ok thanks, I did talk to the Wix Technical support and they did say "its proprietary" and they mentioned that their XP filters are designed to allow larger particles to pass so that it could hold more particles and that is becomes more effective at filtering smaller particles the longer it is...
And as for the B2=20 I have never seen that claim about a Wix filter but I have seen it in many posts. And so if I read your post correctly Wix is saying 2/20=6/20 is the industry standard way of saying B6=2 ( 50% Filtering of 6 Microns ) and B20=20 ( 95% Filtering of 20 Microns ).
It seems the...
I just bough a number of Wix XP Filters and was concerned when I read that they are only filter 50% of 20 Micron Particles I have done some reading that was was based on this B2=20 and was said to mean 50% filtration of 20 Micron particles. I haven't been able to find any specs for the Wix XP...