Posted by a reviewer on Amazon

When i took the filter out and put it sidebyside with the second one they give you it was already noticeable the one that was in one week was already turning brown color

Posted by a reviewer on Amazon

Thats when i knew it was working without slowing the blower down too much i believe its about amber 8 which is fine i dont know what the black stuff is im hoping its carbon but its hard to tell but i do notice a difference and i replaced the first one because its weak to and i put the new one in and i will keep that one in in till spring which is coming fast so probably two more months now i just have to clean all the ceiling fans and windows are even brown thats sad that someone would smoke that much but i am very happy with this filter there is another brand but the merv 15 kind of scared me away i had one before and it just literally almost got sucked in motor was struggling so i do like these and i think i will keep buying them i just was hoping they would give more information about what the black stuff is it looks like its just painted on if its sprayed on carbon thats fine but they should say that

Posted by a reviewer on Amazon

There is a lot of debate on what filters to use too thick may put extra strain on hvac system too thin does not keep air clean etc

Posted by a reviewer on Amazon

My friend returned to her condo which had been rented for the past year to find the tenant had been a heavy smoker although not allowed in the lease

Posted by a reviewer on Amazon

I also cannot find this size in any store and ordering it from the heating company is big bucks

Posted by a reviewer on Amazon

Even after one week we were disgusted to see what this filter was able to trap that our old brand left behind