The lid is almost identical to another lid made by the same manufacturer, and differs mainly in the position of the text
FONTE DUCTILE - DUCTILE IRON (Thanks to McCartney) GS - Spheroidal graphite cast iron - a special cast iron in which the crystallization of carbon has been slowed down, which makes it close to steel - also called ductile iron (Thanks to Vuori Susi for the clarification)