KAIR COWLED WALL OUTLET 100mm x 54mm RECTANGULAR SPIGOT Kair cowled vent with damper flap & 110mm x 54mm square spigot. Designed for use with 100mm / 4 inch rectangular ducting. Cowl protects against driving rain and gusts of wind entering your property via the duct run. Damper flap can be closed to help reduce unpleasant odours, noises, or draughts flowing back through your duct. The female spigot on the back of the outlet fits over male 110mm x 54mm rectangular duct pipe Part: DUCVKC249. Wipe-clean durable design for indoor or outdoor use. Suitable to use in compliance with Part F Building Regulations. Airflow performance independently tested by BSRIA or BRE. Free Air: 7200mm2. Static Pressure Drop in Pascals: 15 l/s: 4.72 Pa - 30 l/s: 17.18 Pa - 60 l/s: 62.48 Pa. Built to last out of high-quality Polystyrene/Polypropylene plastic material. Max / Min Temperature: +60c / -15c. Easy to install and durable, just push-fit duct and fittings together. For permanent fixings, seal joints with silicone sealant or tape. Perfectly suited for ducting your: Bathroom or kitchen extractor fans Hydroponics In-line extract fans Tumble dryers Cooker hoods Passive vents Kair plastic rigid ducting is perfect for DIY and Trade use and provides superior airflow performance and durability versus flexible duct. Covered by the Kair 100% Satisfaction Guarantee. PLEASE NOTE: The cowl comes from the manufacturer with slightly bent sides. This is to enable easy removal of cowl initially so that back plate can be screwed to the wall. Once secured the cowl can be fitted into the back plate and sides pushed so that the side wall clamps click into the back plate.