Holophane brand square wall light in moulded thick glass

Apply or ceiling in a square shape. Holophane brand. 60s and 70s. Thick molded glass mounted on a metal structure ton gray caviar. Glass in very nice condition. Metal structure with rare alterations around the edge and common traces of use on the back (see photos and zoom). Bayonet sleeve. Holophane mark marked in hollows inside the metal structure (see photos). Glass dimensions 18.5 cm X 18.5 cm at the top, 19.5 cm X 19.5 cm in the lower part placed on the metal mount. Height of glass 6 cm.