This is a very high-temperature resistant, sturdy, and integrated pipeline variable diameter increase pipe, which can be used to connect two different solid or flexible pipes or pipelines to a ventilator. Small. Suitable for the HVAC ventilation system, bathroom exhaust, air-cooled hood, embedded fans, hood, roller dryer, hydroponic system, kitchen or apartment, family garage attic or office space use together.SpecificationMaterial: Galvanized SteelColor: Silver ToneBiggest Outer Dia.: 125 mm / 5 Inches.Smallest Outer Dia: 100 mm / 4 Inches.Length: 210 mm / 8.3 inches.Package List: 1 pcs Duct ReducerAdvantageThe duct adapter is made of galvanized steel material, which is not easy to rust and corrode, and the surface is treated very smooth.