Start with your filter size — it's printed on the cardboard frame of your current filter (like 16x25x1). Then compare filtration levels side by side: what each filter removes, its MERV performance rating, technical specs, and replacement cycle.
MERV 4–8
Equipment protection & everyday dust — lint, dust, pollen.
MERV 11
Allergy relief — adds pet dander, mold spores, and smog.
MERV 13
Healthiest air — adds smoke, aerosols, and bacteria-carrying particles.
Size not listed? Measure the length, width, and depth printed on your current filter's frame — nominal sizes are rounded up from the actual dimensions, so always go by the printed size, not a tape measure.