FUNCTION: Allows seamless dust collector connections from 5inch main line to 4inch branch line and/or machines with 5inch ID ports (or hoses) to 4inch ID standard hosesAPPLICATIONS: Ideal for optimizing the performance of your dust collection system and is compatible with an assortment of hoses, ducts, planers, jointers and other tools like the for Super BUILD: Featuring a non-threaded, all-black plastic construction, this reducer fitting was designed for durability and made to withstand the wear and tear often associated with woodworking dust extractionPlease note: the physical slightly color difference or difference, does not affect the use, please do not mind, thank you!4inch OD tapered end to facilitate safe and secure connection with the dust collection hose; and 5inch OD end with 4-57/64inch outer diameter for quick and easy installation of 5inch ID machine portColour:As ShownMaterial:plasticPackage Contents:1 x 5 to 4 Inches Duct ReducerOnly the above package content, other products are not included.Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.