This die-struck gilding metal badge (11.5 x 10.5cm) is the badge for the high combed fire brigade helmet, typical of most of northern Europe in the 19th century. The central feature is the Belgian lion surrounded by flags.

I think this is the early gorget from the start of Belgium as an independent kingdom in 1831. Gorgets were worn round the neck as the last vestige of armour and an indication of officer rank. They were worn in the Belgian army throughout most of the 19th century, normally only by infantry. Cavalry did not wear these, for instance.