The Breitling Emergency, designed for pilots and aircrews, is an instrument watch with built-in microtransmitter broadcasting on the 121.5 MHz aircraft emergency frequency. Following a crash or a forced landing, for example, the Emergency will send a signal on which rescuers can home in. The watch thus serves as a complement to the aircraft’s own distress signaling equipment. The Emergency’s transmitter is activated by unscrewing a protective cap and pulling the antenna out fully. It will then broadcast for 48 hours. Over flat terrain or calm seas, the Emergency transmitter’s signal has a range of about 160 kilometers (100 miles), assuming the search aircraft is flying at 6,000 meters (20,000 ft).