Check the listing for details. Concentric Reducer 4" to 2" HVAC Duct Reducer and Increaser Weld Pipe. Condition: New. Listed at 23.55 USD. This concentric reducer can be applied to various industries, such as refrigeration, mechanical, food, dairy, wine and beverage etc. It's polished, widely used in highly clean and purity piping system. It is an universal pneumatic or hydraulic fittings to connect pipes, tubes, and hoses.Specification:Color: SilverMaterial: 304 Stainless SteelLength: 98 mmInterface outer diameter 1: 102mm/4inchInterface outer diameter 2: 51mm/2inchThickness: 2 mmPacking List: 1 Pcs x Ducting concentric reducerAdvantage:The steel pipe reducer and increaser is made of 304 stainless steel, which has good heat resistance performance, anti-oxidation, anti-rust, durable and corrosion-resistant, and has high hardness. 304 stainless steel is pollution-free. It is mirror polished and has a smooth surface. It's precisely sized, so don't worry about not fitting.