21 1/2x23 5/16x1 Carrier Replacement Filter by Aerostar - MERV 13, Box of 6 Replaces Bryant/Carrier part # KFAFK0412XXL Fits: FV4, FK4, FC4, FB4, FA4, FH4, FA4CNC060, FC4BNB054000AEAA, FC4CNB054, FE4ANB006, FK4DNB006, FV4BNB006, FX44B, FX4CNF060 Pleated MERV 13 Media Comparable to MPR 1500 to 1900 and FPR 10 Designed for Superior Filtration Efficiency Made with electrostatically charged synthetic material that draws and captures allergens between 0.3 - 1.0 microns, including lint, dust mites, spores, pollen, pet dander, fine dust, smoke, viruses, and bacteria. Reduce Cost An Aerostar furnace air filter helps keep your HVAC unit working efficiently by removing dirt and reducing strain on the motor. When your unit runs properly, it consumes less energy, requires less maintenance and will have a longer life. These factors will have an impact on your utility bill and maintenance costs. It is recommended that you change the filter every 60 to 90 days during normal times of year but increase frequency to 30 days during peak summer and winter months when your unit is working the hardest. About Aerostar Air Filters Aerostar filters are manufactured in the USA by Filtration Group, a world-leading manufacturer and supplier of filtration solutions for residential, commercial and industrial applications. The Aerostar brand is known for constantly innovating and improving their technology to help make filtration more efficient, effective and environmentally friendly every day. What's in the BoxBox of six Aerostar MERV 13 Pleated Furnace Air Filters. MERV 13 filters are comparable to MPR 1500 to 1900 and FPR 10Nominal Size: 21-1/2 x 23-5/16 x 1, Actual Size: 21-1/2" x 23-5/16" x 3/4" , Size: 21 1/2x23 5/16x1, AC and Furnace Air Filters