Whynter Portable AC Hose Connector/Extender Kit. Three pieces connect together to extend the length of the exhaust hose. They are also the same pieces used to attach the exhaust hose to the machine and to the window panel. Manufacturer part number ARC-HCSET.
Please note: You can also purchase additional hoses for your model. Check the Accessories tab on your AC's product page to find one that matches your model.