Air conditioner exhaust coupler/adapter/connector/interface! Basically, the thing that attaches the big pipe to the air conditioning unit! This one is rectangular and from a Wood's AC Milan Portable Air Conditioner. I have no idea whether it fits other brands but I have put as much detail as I can in the photos so that you can work it out! The rectangular side that slides onto the air conditioning vent is 17.5cm x 11.5cm (external) and slides onto the back of the air conditioner as shown. The tube/hose/pipe thing that it fits is the standard 15cm diameter pipe and it sort of screws into the circular side with protruding plastic bits to hold it in place. If you have any questions, do please ask.
