20 X 20 Replacement Filter. Fits Honeywell F200E1011, F100F1020, and F100F2036 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%