Square Stainless Steel Dryer Air Outlet External Wall Check Valve Cover, 4-inch 100mm With Insect Netting, 5-inch 125mm With Insect Netting, 6-inch 150mm With Insect Netting, 4-inch 100mm Without Insect Netting, 5-inch 125mm Without Insect Netting...

1. Material: stainless steel
2. Pipe connection: round or square pipe interface, adaptable to exhaust pipes of different diameters
3. Silent design: a sponge sheet is fixed inside the vent to reduce operating noise when the cover opens and closes.
4. Sealing gasket: The outer edge of the product is equipped with a rubber sealing gasket (rubber material) for adhesion to the wall or pipe opening during installation.
5. Suitable for exhaust pipe ends in dryers, bathrooms, kitchens, garages, etc.
6. The product has an automatic damper mechanism that opens and closes based on airflow pressure to prevent external rainwater, sand, and debris from flowing back into the pipe.
7. When hot or cold air is discharged from the pipe, the internal cover automatically opens to release air.
8. A sealing structure is provided on one side of the cover to reduce air backflow and debris entering the pipe.
9. 4-inch (100 specification): pipe interface outer diameter 98mm; panel length 165mm; panel width 185mm; overall depth 50mm
10. 5-inch (125 size): duct connector outer diameter 121mm; panel length 165mm; panel width 185mm; overall depth 50mm
11.5-inch (150 size): duct connector outer diameter 145mm; panel length 165mm; panel width 185mm; overall depth 50mm

The product is designed for easy installation. Installation steps are as follows:
1. Place the rubber sealing gasket around the outer edge of the vent.
2. Insert the duct connector into the exhaust pipe (compatible with both metal and plastic ducts).
3. Secure the vent using the included screws through the pre-drilled holes on the product.
4. The product has retaining teeth on the inside to help secure the vent cover to the duct and prevent it from loosening.