Duct Multi Reducer Extractor Fan Pipe Connector 80/100/110/120/150/160mm Ventilation Pipe Reducer Adapter Plastic Pipe Fitting - AliExpress
Amazon.com: Vent Systems 4'' Inch 45 Degree Duct Connector 3 Way Hose Adapter/Splitter for Hose T-Shape Round Pipe Connector- Extractor Fan - Duct Hose Dryer Vent T Connector - 4 Inch 3
Panasonic WhisperGreen Select Pick-A-Flow 110/130 or 150 CFM Quiet Exhaust Fan Flex-Z Fast Install bracket + 6 in. Duct Adapter FV-1115VK2 - The Home Depot
Have a question about Panasonic WhisperThin Pick-A-Flow 80 or 100 CFM Exhaust Fan with LED Light Low Profile Ceiling or Wall and 4 in. Oval Duct Adapter? - Pg 5 - The Home Depot
Master Flow 4 in. to 3 in. Round Reducer R4X3 - The Home Depot
Panasonic WhisperGreen Select Pick-A-Flow 110/130 or 150 CFM Quiet Exhaust Fan Flex-Z Fast Install bracket + 6 in. Duct Adapter FV-1115VK2 - The Home Depot
3D Printed 90mm exhaust fan adapter to 3inch duct Anycubic Photon by Jacob Baker | Pinshape
Amazon.com: MagiDeal 3 Way Duct Connector, Duct Splitter for Exhaust Fan Hose, Y Shape, 19.5cm : Appliances