100 mm White Plastic Gravity Wall Grille with Non-Return Shutter and 4 inch Round Spigot for Bathroom Kitchen Cooker Hood Extractor Fan Ducting Air Hose Wall Ventilation

Durable white plastic ducting with built-in air inlet/outlet and gravity shutters. It measures 155 mm x 155 mm externally and has a 4-inch/100mm round male rear spigot for both indoor and outdoor applications. The flaps close by themselves when not needed, stopping bad smells, noise, or drafts from coming back through your duct. They work without springs to avoid any chance of breaking. Simple installation - effortlessly connect duct and fittings by push-fitting. Ideal for use as a Bathroom or Kitchen extractor fan, Hydroponics fan, or In-Line Extract Fan. This grill is useful in long duct systems for different things like ventilating the whole house, passive ventilation, bringing in fresh air, air conditioning, and heating systems. This product meets Part F Building Regulations and has been tested for airflow performance by BSRIA or BRE. It allows for 7200mm2 of free air, and the pressure drop is 10.94 Pa at 15 l/s, 18.59 Pa at 30 l/s, and 24.21 Pa at 60 l/s., Manufacturer: NESVENT