AAF Flanders 10x20x2 Furnace Filter Merv 13 AAF (12-pack) MERV 13 filter : Highest Efficiency filtration. The PREpleat M13 pleated filter by AAF Flanders has a low initial resistance and supports achievement of LEED® credits by significantly improving Indoor Air Quality (IAQ) and reducing... MSRP: Was: $271.00 Now: $247.00 Add to Cart