Kair Ducting Reducer 100mm to 80mm 100mm / 4 inch Side 100mm male and will fit inside Kair 100mm straight ducting Part: DUCVKC250 without the need for a connector. 80mm Side On the other side there is a 80mm male spigot. Will fit into 80mm female fittings or flexible ducting. Can be used with rigid plastic ducting systems - seal with mastic or tape. Can be used with flexible ducting systems with use of metal hose clips. Max / Min Temperature: +60c / -15c. Kair plastic rigid ducting is perfect for DIY and trade use. Perfectly suited for ducting your Tumble Dryer, Bathroom or Kitchen extractor fan, Hydroponics, In-Line Extract Fans, or Cooker Hood. This reducer can be used as a part of a long ductwork run for a variety of purposes including whole house ventilation, passive stack vent, positive input, air conditioning, HVAC, and Heat Recovery Systems.