The current rolling stock of the Chicago "L" rapid transit system consists of three series of railcars. The oldest series is the 2600-series which was built between 1981 and 1987 and refurbished between 1999 and 2002. The second series is the 3200-series, built between 1992 and 1994 and refurbished between 2015 and 2018. The third and newest series is known as the 5000-series; built between 2009 and 2015, they feature new technologies such as LED color signs, security cameras, new seating configuration, AC motors, and interior LED signs displaying date and time.