Stainless Steel Material The extractor fan vent cover is made of genuine 304 stainless steel material, which is not afraid of sunlight and rust; it is not afraid of wind and rain and is corrosion-resistant. Rugged and durable features effectively extend the service life of the product. Easy InstallationThe package includes an external square air vent cover for 100mm ducting with a 15.5x15.5cm square rubber ring and 4 3.5x40mm screws. Can be used for indoor and outdoor wall mounting. Simply push the exhaust pipe into the outboard exhaust cap port, it is held in place by 4 screws, and installation is done in a few easy steps. Anti-Biological Technology The extractor vent cover has a built-in flip cover, which can more effectively prevent birds or other pests from entering the duct compared to the vent without a flip cover. Effective ventilation can better protect the safety of you and your family. Quiet and ComfortableThe flaps can be closed to help reduce unpleasant odors and airflow back through the ducts, the included rubber seals, and a foam plug is installed inside the hood to effectively reduce noise. Note: With the air flow, in order to maintain a better seal when it is closed, there will still be some sound, please forgive the inconvenience to you! Wide Range of Uses Cowled external square air vent covers are easy to clean and resistant to dirt, unlike ordinary grilles, dust builds up and easily clogs over time, universally suitable for vented tumble dryers, bathroom fans, kitchen fans, offices, garages, sheds, camping vehicles, range hoods, etc. and other industrial uses.