Caterpillar Inc. is a manufacturer of construction and mining equipment, diesel and natural gas engines, industrial gas turbines and diesel-electric locomotives. The Company operates through its three primary segments: Construction Industries, Resource Industries and Energy & Transportation. It also provides financing and related services through its Financial Products segment. Its Construction Industries is engaged in supporting customers using machinery in infrastructure, forestry and building construction. Its Resource Industries is engaged in supporting customers using machinery in mining, heavy construction, and quarry and aggregates. Its Energy & Transportation, which supports customers in oil and gas, power generation, marine, rail and industrial applications, including Caterpillar machines. Its All Other operating segment, which includes activities, such as product management and development, manufacturing of filters and fluids, undercarriage, ground-engaging tools, and others.