The FAMCO TR Tapered Reducer is designed to reduce the duct size of a forced air run is a short transition. By gradually decreasing the duct size, the maintains the CFM, prevents a large loss of CFM, in the run and maximizes air flow. Quality constructed in 26 gauge Galvanized steel. The FAMCO TR Tapered Reducer comes in a range of sizes from 4 inch x 3 inch to 18 inch x 16 inch. Custom sizes are also available. The FAMCO TR Tapered Reducer 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, variations or custom orders, please refer to the FAQs above or feel free to contact us by phone or email.