This PC card is external equipment and a serial I/O card dealing with PC Card Standard conformity CardBus which performs serial communication of RS-232C conformity. It can be used being able to insert in a PC Card Standard conformity CardBus correspondence PC card slot. It has the serial port of two channel by one board. The driver for Windows and Linux appending. It operates on Windows XP, 2000, Me, 98SE, 98, and Linux.