Review on Premium Cabin Air Filter Performance Replacement Parts ... Engine Cooling & Climate Control by David Cronin

I used to have regular paper filters and they suck, then I switched to Fram Fresh Breeze (2 years) and they were better, but these KNN cabin filters are even better, they are the best at blocking fumes. Both were not 100% but still better than Fram's fresh air filters and they have better airflow too. Now when I run my fan on level 2 it seems to run on level 2.5 compared to paper filters, the only thing is that it smells a bit like rubber but I hope this smell will go away within a month, but that's ok as it's not strong enough to give me a headache or anything, it's a very very light smell. I love the fact that these filters have a rubber rim that really seals the air filter compartment and that's probably why it blocks fumes so well, unlike paper filters that just pop in and get stuck there, so that's a big plus . . The other thing is they don't have an arrow showing the direction of the airflow so it looks like they could be placed either way but pay attention to which direction the air is going as I've noticed that the KNN filter is more flexible. one side and not the other, so think about how the air will pull it in and make sure it's there so it doesn't bend as the air sucks it down.