United Technologies Corporation (UTC) provides high technology products and services to the building systems and aerospace industries. It has six segments: Otis, Carrier, UTC Fire & Security (UTC F&S), Pratt & Whitney, Hamilton Sundstrand and Sikorsky. Otis includes elevators, escalators, moving walkways and services. Carrier includes heating, ventilating, air conditioning and refrigeration systems and equipment, and food service equipment. UTC F&S offers electronic security, fire detection and suppression, monitoring and response systems and services, and security personnel services. Pratt & Whitney includes military and commerical aircraft engines, parts and services, industrial gas turbines and space propulsion. Hamilton Sundstrand includes aerospace products and aftermarket services. Sikorsky offers military and commercial helicopters, aftermarket helicopter, and aircraft parts and services.