Kair Ducting Reducer 150mm to 100mm - 5 to 4 inch150mm / 5 inch Side150mm female socket (the same diameter as rigid 150mm ducting pipe). Male fittings such as connectors, bends, and grilles will fit straight in to the socket.If you wish to connect this to Kair 150mm Straight Pipe Part: DUCVKC650 you will require a male connector / coupling Part: DUCVKC365.Kair 152mm Flexible Hose Part: DUCP0092/152/35 will fit over and require tape or metal hose clip or quick release worm drive clip to seal100mm / 4 inch Side100mm male and will fit inside Kair 100mm straight ducting Part: DUCVKC250 without the need for a connector.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.