A:Answer Alex, are you referring to the exhaust nozzle? When I was setting my unit up, I pulled the exhaust tube to extend it and the nozzle came off. It was a royal PITA to get it back on. After that, once you put the nozzle into the window bracket, it will slide left or right inside the bracket to lock in place. It's not a real tight lock but should be enough to keep it from falling out. Hopefully that helps