Air vent in the airplane
Airplane windows have a small opening at the bottom edge. This has two purposes. The first purpose is to allow the airflow to escape. This prevents too much pressure in the aircraft cabin and also prevents the windows from breaking as the altitude rises. The other reason for this opening is to prevent the windows from misting up. This would actually happen due to the warm breath of the passengers. However, the opening prevents this, which is why it is so important and necessary.
Vent valve in the airplane
Grille in the microwave door
The microwave is a good example of the Faraday cage. During operation, strong microwave radiation is emitted in the metal cooking chamber. However, to ensure that little or hardly any of these rays reach the outside, each microwave window has the familiar black grid. This largely protects the surroundings from the radiation. This electrical shielding consists of a wire mesh or sheet metal. Incidentally, you should not look into the microwave for too long, as they are poor at dissipating the heat generated.
Grille in the microwave door