20 X 25 Replacement Filter. Fits Honeywell F200E1037, F100F1038, F100F1087, F100F1098, F100F2010, F100F2044, and F100F2051 Models. MERV 13 at 492 FPM 0.3 to 1.0 microns = 57% 1.0 to 3.0 microns = 82% 3.0 to 10.0 microns = 91%