Petroleum Operations, a division of U.S. Oil Company, maintains several bulk storage terminals and gas stations throughout the Midwest. It provides a variety of wholesale and branded petroleum products for residential and commercial clients. The division supplies and distributes products from the BP-Amoco, Conoco-Phillips 66, Exxon, Mobil and Shell brands. Additionally, it is engaged in the selling and buying of convenience stores and petroleum-related real estate properties. The division owns and operates more than 10 fuel storage and wholesale distribution facilities in Wisconsin, Illinois, Indiana and Iowa. Its terminals are equipped with computer-controlled security systems, as well as allow 24-hour access to authorized customers. Petroleum Operations has a storage capacity of over 120 million gallons. U.S. Oil Company is a group of businesses that also operates the Design Air, U.S. Oil Lubricants and US OilChek divisions.