When you're running your furnace or air conditioner, that's a lot of air being forced through your ducts. That's also a lot of gunk circulating through your furnace. Thankfully, with a MERV 11 rating, you know that this filter is up to the task. That rating indicates that your new filter will remove over 95 percent of all irritants and pollutants that are about 1 micron or larger. That includes mold, dust mites, pet dander, and pollen. When this filter is on the job, you can breathe easier mentally and physically. For maximum efficiency, make sure to inspect your filter monthly and change it every three months.