NESVENT 2 x 100mm Backdraught Shutter Flap 4-inch Non-Return Valve Damper Flap to Connect Duct Pipe or Flexible Ducting Hose Backdraft Cold Air Stopper

Ventilation systems are intended for air distribution in ventilation systems of flats, houses and utility buildings. Perfect for where the air should not go back, and only fresh air should remain. Pipe to pipe connection. 100mm / 4-inch Plastic Ducting Connector with backdraught shutter / non return damper flap Male Spigot will fit inside 100mmRound Pipe 102mm Flexible Hose and can be used to join multiple lengths of pipe together to form a long duct run. Stops unpleasant odours, noises, or draughts flowing back through your duct. With a gravity flap - no need for springs that break! Use when you need to stop smells flowing backwards with inducting, or when you have 2 or more extractor fans connected to same duct run. Round rigid ducting provides superior airflow performance vs. comparative size rectangular or flexible duct. Pressure Drop in Pascals: 15 l/s = 25.0 Pa - 30 l/s = 44.90 Pa - 60 l/s =101.60 Pa. Easy to install and durable, just push-fit duct and fittings together. Built to last out of high-quality white Polystyrene/Polypropylene plastic Material. Max / Min Temperature: +60c / -15c. Suitable to use in compliance with Part F Building Regulations.