The C4P was a Polish half-track artillery tractor developed in the 1930s. Based on the Polski Fiat 621 truck, it featured a tracked rear suspension and a wheeled front axle, which gave it better off-road mobility. It was mainly used for towing artillery pieces such as the 75 mm and 105 mm guns, as well as for transporting crews and equipment. The C4P served in the Polish Army during the 1939 campaign, proving useful but available only in limited numbers.