A: They did not restrict the flow of air from my heating ducts. They worked great at catching what my A/C filter didn’t, I feel better and breath better with the extra filter protection.
A: The filters go between the grill and the moveable fins that open and close off the air.
A: Yes, they are white but a life saver and you can see them once they are installed.
A: Yes, white is the only color I've seen, so far. It would be nice to see different colors (hint hints, maybe someone will find this idea interesting enough to create colors). I've been using these things for so long that I'm used to seeing it & the white color doesn't phase me anymore. Air flows through easily and helps keep dust from flying arpound and bugs from coming in.
A: They are white and you can see them in the registers. Mine did a good job and turned grey as they catch stuff in the air flow. This means they are doing their job.
A: Yes they are white, but I don't even notice them.
A: Yes they are white, you can see them thru the vent like you do with an indoor air filter.