Caterpillar manufactures construction and mining equipment, diesel & natural gas engines, industrial gas turbines, and diesel-electric locomotives. The company operates through 4 segments, namely, construction industries, resource industries, energy & transportation, and financial products. Caterpillar's product and services portfolio includes reciprocating engines, generator sets, marine propulsion systems, gas turbines, and turbine-related services. Caterpillar, Inc. supplies power rental equipment through its energy and transportation segment. The segment supports customers in the oil & gas, power generation, marine, and rail industries.