AAF Flanders 16x25x1 Furnace Filter Merv 13. (12-pack) $16.50/each 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)... MSRP: Was: $218.00 Now: $198.00 Add to Cart