The shield is composed of nine gradually overlapping circular diaphragms, which create louvers around the sensing unit. This enables free flow of air between the diaphragms. The body of diaphragms and the base is made from plastic, connecting material is made from stainless material or aluminium alloys.

To ensure better screening of luminous or thermal energy, the inside surface of diaphragms are painted in matt black colour and it is not smooth, but it is indented as well. The shield design enables - with help of a bolt - its quick installation on the mast arm, and with help of the cable bushing with the thread Pg 29 - an easy fastening on the sensing unit inside the shield.