Duststop DP-2020PR2 Premium Air Filter, 20 in L, 20 in W, 8 MERV

Not only do these filters have a MERV 8 rating, which means that it removes nasty particles like mold spores, hair spray, dust mites and animal dander from the air you breathe, but they're designed to last 1 to 3 months too, so you won't be forever changing your filter.