The lighting cover that should be in Ramat Gan is in Kiryat Ono. This cover is also found in Tel Aviv ("Bug" category as well) Click for cover's details
GJS-500-7 also called GGG50 marks a strong and heat-resistant type of metal while GJS is a sign for Continuously Cast Spheroidal Graphite Iron - which describes a process in which the metal is continuously fed.
Translation of the text on the cover: Ramat Gan Municipality The emblem of the city of Ramat Gan IS 489 600 D400 EN124 lighting Cork must be locked RAD-YH CHINA On the frame: GJS 500-7 D400 2018