The D.445 is a class of four-axle diesel locomotives for use in passenger service. They are being powered by a FIAT V12 with 1,560 kW or 2,090 hp that is connected to a large generator for traction and a smaller generator for train supply. Like on many French locomotives, each bogie has only one traction motor that transmits its power via a dancing ring to both axles. Top speed is 130 km/h. With maximum load on the train supply generator, 1,140 kW or 1,530 hp are available for traction.

Three batches of 35, 20 and 95 locomotives were built by FIAT between 1974 and 1988 with additional equipment from Sofer and Officine Meccaniche Calabresi. The first batch could be distinguished by rounded front windows and only weighed 72 tonnes. The two other batches had flat windows, multiple controls and were four tonnes heavier. They were not only used on the Italian mainland, but also on Sardinia. Until today, more than half of the class has either been stored or scrapped after being replaced by DMUs.