Lennox X1152 MERV 11 Filter - 20" x 25" X 5" Replace every 6 months in normal use Genuine Lennox OEM Filter MERV 11 Efficiency to capture particles as small as 0.3 microns Actual Size: 19.65" x 24.65" x 4.31" Use in Trion Air Ber 453000-001, Supreme 2000, 455602-111 and 447380-002 Air Cleaners