It is both an RS232 shield and also an RS485 Shield for Arduino. It can easily convert UART to RS232 or RS485 interface. The shield integrates DB9 connectors (female) that provides a connection to various devices with RS232 interface and also provides an RS485 screw terminal interface. It provides a prototyping area to make the full use of extra space on it which is highly convenient for prototyping.
This shield provides 2 mode setting switch. UART/Soft serial setting and RS485/RS232 setting switch. When UART/Soft serial switched to Soft Serial, you’ll be able to program the Arduino controller or communicate with soft serial; when switched UART, you can use the UART port.