Installing the stainless steel non-return valve in your kitchen or bathroom exhaust duct is a straightforward process. Simply insert the valve into the duct and secure it in place. This valve is designed to automatically close when the exhaust fan is not in use, preventing backflow and ensuring that your home remains from unwanted . Features - Color: Silver -Material:Stainless Steel - Size: 19.00X19.00X4.50cm/7.47X7.47X1.77in - Size: 15.00X15.00X4.50cm/5.89X5.89X1.77in -Multipurpose use: ideal for dryers, extractors, range hoods, and other hvac applications, offering versatile use across different systems -Effective backflow prevention: equipped with a check valve to prevent the backflow of smoke , maintaining a clean environment -Installation: simple installation process makes it for kitchen and bathroom range hoods, requiring no assistance -Quiet performance: designed for silent operation, ensuring no noise disturbance during use, providing a serene home environment -Adjustable airflow control: features an adjustable valve to cater to different airflow requirements, ensuring flexibility and optimal list: 2 pcs x 1pcs valve