how do i stick this to my air con? its 125mm connector on the air con but the window and pipe is 150mm and threaded, but cant find a threaded version!

I don’t see anything in the Kair range that solves your problem. The 150 -125mm reducer is just slip-on and it worked fine in my situation. Does the Air-con manufacturer have a fixing to take you from thread to smooth or technical department you can approach for advice? If all else fails You could try to make a connector from flexible hose and fasten with glue and large jubilee clips. Sorry I can’t be more help.

How is this fixed to the other pipe? Does it need a jubilee clip and if so, is it sufficent to fix it in place?

This is more designed to reduce the size of the fitting on a fan and isn't designed to put two pipes together. With that in mind, to make it work for that, both of your pipes would need to be an adequate size to fit over both sizes of the reducer and a jubilee clip would suffice to hold it in place.

My bathroom extractor fan is 100mm but the ducting is 110mm. This reducer seems to be the ideal solution to remove the gap - is it?

It is, although this is designed to fit ducting so you may need a short sleeve of 100mm ducting between the reducer and your fan.

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Kair 150mm to 125mm Round Duct Reducer

Product ID: 51940328

Details

Brand
Kair
Colour
White
Connector type
Coupling
Item dimensions L x W x H
15.5 x 15.5 x
Item weight
0.09 Pounds
Material
ABS Plastic

📏150mm to 125mm precision fit

🔧Universal spigot compatibility

🌬️Optimized airflow for ventilation

¥3624

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Description

🔄 Upgrade your airflow game with the ultimate duct reducer!

UK MADE QUALITY - Proudly manufactured in the UK, trusted by thousands with a 4.5-star rating.
MULTI APPLICATION READY - Ideal for tumble dryers, extractor fans, hydroponics, and kitchen ventilation setups.
VERSATILE COMPATIBILITY - Fits over 150mm male fittings and inserts into 125mm ducts, including flexible options.
DURABLE ABS CONSTRUCTION - Lightweight yet robust ABS plastic ensures long-lasting performance in any environment.
SEAMLESS SIZE TRANSITION - Effortlessly adapts 150mm ducts to 125mm systems for perfect integration.

The Kair 150mm to 125mm Round Duct Reducer is a precision-engineered ABS plastic adaptor designed to seamlessly connect 150mm and 125mm ducting systems. Compatible with a wide range of fittings and flexible ducts, it’s perfect for enhancing ventilation in dryers, extractor fans, hydroponics, and kitchen hoods. Lightweight, durable, and UK-made, it’s a top-rated solution trusted by thousands of professionals and DIY enthusiasts alike.

Specifications

ASIN	B004X4SXBM
Best Sellers Rank	3,971 in DIY & Tools ( See Top 100 in DIY & Tools ) 6 in Ducting
Brand	Kair
Colour	White
Connector Type	Coupling, Reducer
Customer Reviews	4.5 4.5 out of 5 stars (2,631)
Item Dimensions	15.5 x 15.5 x 6 centimetres
Item Highlight	Fits over fittings (bends etc), For dryer vents and cooker hoods and extractor fans, Suitable for grow tents and hydroponics
Item Weight	0.09 Pounds
Manufacturer	Kair
Material	ABS Plastic
Number of Packs	1
Number of Pieces	1
Part Number	DUCVKC619
Size	150mm to 125mm
Thread Size	150mm, 125mm
Thread Type	UN
Unit Count	1.0 count

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¥3624

Duties & taxes included

In stock

Sold byAmazon JapanDelivered byDesertcartCustomer service byDesertcartReturns14 days · 30 with PRO

Buyer Protection · Full refund if your order doesn't arrive as described.

Desertcart purchases this item on your behalf and handles shipping, customs, and support to Japan.

Secure transaction

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TrustScore 4.5 | 7,300+ reviews

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