The FAMCO FR Furnace Filter Rack is made to hold up to a 4 inch furnace filter. Easy filter access with use of snap clips and simplified “door”. Quality constructed in 28 gauge Galvanized steel for durability and longevity. The FAMCO FR Furnace Filter Rack come in a range of sizes to fit common sized ducting: 14 inch x 20/25 inch, 16 inch x 20/25 inch, 18 inch x 20/25 inch, and 20 inch x 20/25 inch. The FAMCO FR Furnace Filter Rack is manufactured by FAMCO in the United States and comes with a 1-year warranty against product defects and workmanship. If you have any questions about this product, please refer to the FAQs above or feel free to contact us by phone or email.