21 1/2x23 5/16x1 Carrier Replacement Filter by Aerostar - MERV 8, Box of 12 Replaces Bryant/Carrier part # KFAFK0412XXL Fits: FV4, FK4, FC4, FB4, FA4, FH4, FA4CNC060, FC4BNB054000AEAA, FC4CNB054, FE4ANB006, FK4DNB006, FV4BNB006, FX44B, FX4CNF060 Pleated MERV 8 Media Comparable to MPR 600 and FPR 5