100mm / 4 inch Kair Plastic Ducting Connector with backdraught shutter / non return damper flap Male Spigot will fit inside Kair 100mm Round Pipe Part: DUCVKC250 or 102mm Flexible Hose Part: DUCP0092/102/35 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 within ducting, 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. For permanent fixings, seal joints with silicone sealant or tape Will join any Female part of the Kair System 100 range. 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. Search for Kair Ducting for the full range of compatible Round and Rectangular fittings, outlets, and grilles.