One of the most famous buses to come from the FIAT stable is this model called the 412 Bipiano, a double-decker. 

This coach was built by a Naples based firm called AERFER (Costruzioni Aeronautiche e Fer Roviarie) that made aeroplanes as well as built bus bodies in the 50s and 60s. The bus was a self-supporting structure built completely out of an aluminium alloy called Metropol VE411. With a FIAT made 412.H/61 horizontal engine that gave 176 hp, it could run to a top speed of 50 km/hr.

Because of her low floor, the bus was preferred by kids and aged passengers. With three doors, a passenger could go to the upper deck from the central door where the conductor would be seated and dispersed bus-tickets. 

These buses were seen in Florence, Italy right until the 1980s.