Observation port assembly

An observation port assembly in combination with a vertical panel, such as a door or the like and in which said vertical panel includes inner and outer vertical surfaces, said vertical panel having a through-aperture in which said observation port assembly is mounted for permitting an observer, at the inner surface of the vertical panel, to unobtrusively observe the area at the outer surface of the vertical panel, the improvement characterized in that said observation port assembly comprises:

• a box-shaped housing part including means for fixed attachment to the outer surface of said vertical panel and in said through aperture, said box-shaped housing part including a plurality of separate optical viewing elements each having viewing-oculars adjacent each other and accessible for viewing from the inner surface of said vertical panel, the separate optical viewing elements having a linear optical axis at a predetermined angular relationship to the linear optical axis of an adjacent optical viewing element, the box-shaped housing part including a portion projecting beyond the outer surface of said vertical panel and comprising diverse surface portions in which said viewing elements are fixedly mounted, said housing part having an inner wall, and fastening means extending from said inner wall of said housing part and the inner surface of said vertical panel, said housing part enclosing said fastening means and preventing access to said fastening means from the outer surface of said vertical panel.