A duct reducer is for adapting your ventilation system to accommodate various duct sizes. Whether you're upgrading your HVAC system or installing a new commercial setup, this component ensures a smooth transition between ducts. To install, slide the reducer into the duct and fasten it securely with screws or adhesive. Features -Color:White -Material:Pvc -Size:18.00X18.00X10.00cm/7.07X7.07X3.93in -Optimal backflow protection: this check valve provides optimal protection against backflow, keeping your kitchen away from unwanted smoke and odors -Multisize compatibility: fits ducts, making it a versatile solution for various duct sizes -Sturdy construction: crafted from pvc plastic, this exhaust vent cover is built to last and withstand regular use -Effortless installation: the design allows for easy and quick installation, making it an addition to your kitchen -Noise reduction feature: the sealed design not only prevents backflow but also reduces noise, providing peaceful kitchen environment Package list: 1 x Range Hood Check Valve