OUTDOOR PROTECTIVE GRILL: One of the possible elements of the outlet end point of the ventilation system (e.g. ventilation fan, hood, etc.). The protective grid with low pressure loss and free of moving elements provides rain protection and protection against physical impact, it can be installed on both vertical and horizontal surfaces. The protective grille does not have a pipe socket, so it can basically be fitted to rigid-wall ventilation pipes that are led out to the plane of the outdoor surface. Applicable: for rectangular duct systems with a cross section of 75 x 150 mm, placed on the external side wall.