This is an antique French carriage clock with glass and brass case with enamel decoration that was produced by Vincenti & Cie of Paris. They earned the Medaille d’Argent at the Universal Exposition in Paris in 1855 and their business ceased in 1870, thus dating your clock to post 1855 and no later than 1870.
The estimate is based on actual recent past recorded auction sales of comparables. Retail 'asking prices' can be higher and vary.