4" to 3" Inch Duct Reducer Round Reducer Duct Fitting Pipe Increaser Reducer Made from Galvanized Steel (Drain, Waste and Vent) Reducing Coupling (Metal, 4 to 3 Inch)

100mm Male to 80mm Male Round Ducting Adaptor. 4" (3.93") to 3" (3.15") Can be used with HVAC systems, bathroom extractor fans, inline ventilators, cooker hoods, tumble dryers, hydroponics, kitchens or, anywhere else in the apartment, home or office space. Sturdy Steel ducting is perfect for DIY and Trade use. This is a very practical robust, all in one, solid duct reducer or increaser which can be used when connecting two different, solid or flexible ducts or ducts to ventilators, or vice versa, from small to large, larger to small. Perfectly suited for ducting your Tumble Dryer, Bathroom or Any type of extractor fan, Hydroponics, In-Line Extract Fans, or Cooker Hood.