Lennox 20x25x5 X0586 MERV 11 Box Replacement Filter for Lennox and Honeywell Filter Rating: MERV 11 Filter Size: 20&quot; x 25&quot; x 5&quot; Captures particles down to 0.3 microns Expected Duration: 6 to 12 months Replacement for FC100A-1037 &amp; FC200E-1037