The present invention discloses an assembly that can be used in windscreen wipers of vehicles and is consisting of an adapter and a nozzle structure, and also the assembling method thereof. Here the adapter (1) presents a first adapter assembling feature (1a) and a second adapter assembling feature (1b). The nozzle structure (2) presents a first nozzle structure assembling feature (2a) and a second nozzle structure assembling feature (2b). The first adapter assembling feature and the first nozzle structure assembling feature are matched with each other to form a first connection in the form of pin - circular aperture between the adapter and the nozzle structure, and the nozzle structure and adapter are rotatably pre-assembled together when they are connected only be means of the first connection. The second adapter assembling feature and the second nozzle structure assembling feature are matched with each other to form a second connection in the form of snap fit between the adapter and the nozzle structure. T