This is a "3 in 1" product for additional serial ports and for integration with lighting systems and thermostats. Jumpers on the M1XSP select the appropriate application, connection, and protocol. Best of all, the M1XSP operates from the 4-wire (RS-485) M1 Keypad data bus, allowing RS-232 ports to be located long distances from the control. The M1 Gold and M1EZ8 support up to 7 M1XSPs. The communications baud rate is adjustable from 300 to 38,400 baud. The unit comes complete with cable and a black surface mountable housing.