Otis is a major business unit of United Technologies Corporation, a company comprising such industry leaders as Carrier (heating and air conditioning), Sikorsky (helicopters) and Pratt & Whitney (aero engines) . Otis sells, manufactures and installs over 33,000 elevators and escalators annually, and its mechanics and agent representatives maintain in excess of 700,000 elevators and escalators in virtually every country of the world. It has more than 1.2 million elevators in operation globally, on behalf of approximately 370,000 new-equipment and service customers.