Review on Versatile Cut-to-Fit Carbon Pad Pre-Filters for Air Purifiers, Furnace Filters, Trash Cans, and Air Conditioner Filters (1) by Pamela Begay

Good quality product for many uses. I use heat pump pre-filters in my allergy free air purifiers as a replacement when I run out of my expensive filters, also works well in conjunction with your standard metal oven/stovetop filters, cut to size and attaches to existing filters on the outside/ Bottom of existing filter but ensure it is securely fastened or it could be pulled into the duct if you don't. I recommend using double sided tape or strong paperclips etc. They help get rid of the smell while cooking especially if you are frying something. I have also used this for air conditioner vents, removing the vent and placing it on top to allow cleaner air into your home. There may be some reduction in airflow depending on the device, but I didn't notice any difference. You can also place small air fresheners on top around the edges, again consider possible airflow issues. I glued some to the channel vise on top of the filter.