Serial to USB adapter connects a 9 pin or 25 pin RS232 serial device to your computer through a USB port, as though the computer offered an onboard serial port. The USB to RS232 cable is built with FTDI chip to support you the widest possible OS compatibility and reliable data communication. The integrated 4-foot (1.2 meter) cable allows it to be connected directly from the serial device to the computer without requiring additional cables. This saves you the annoyance of needing an extra adapter.