The Republic of Neuchâtel
It requires that Switzerland owns the province Neuchâtel in West Switzerland and that Prussia has a core on said province. On top of that Switzerland have researched Romanticism and have a prestige score of at least 1. Switzerland starts the game with more than 1 prestige.
It gives 5 prestige, and changes relations with Prussia by 20 and removes the Prussian Core on Neuchâtel.