Trans-Lux is a major manufacturer of real-time displays, and became known for their stock market tickers. Their range including mechanical ones that appeared electronic by using yellow dots and a black background to give the illusion of green electronically-generated green lettering as the letters ran across the front of the machine. The machines were leased, not sold. Since the 1970s, their world headquarters and main production facility is located in Norwalk, Connecticut, USA.