Lasts Much Longer Than 1 Inch Filters.
I bought these to filter the air a little better for my wife due to allergies.  I had bought many of the store brand and they just don't last very long before they start whistling and seem clogged.  I found these and bit the bullet.  Kinda expensive but man was I impressed.  I've been using them for a while now and no whistling.  They filter well it seems because the wife isn't having issues with coughing at all.  I have no real way to test other than her.
Rating: 5 stars