The CLAUSB is designed to make serial port expansion quick and simple. It is designed with an external 4-pin DIP switch to set RS-232, RS-422 or RS-485 mode conveniently, without the need to open the metal chassis. Both a 6-pin terminal block and a DB9 male connector are available for optimal flexibility for serial connection. DIN-rail bracket for industrial environment. The CLAUSB provides instant connectivity to RS-232, RS-422 and RS-485 communications devices. Complete drivers support Windows 98, ME, 2000, 2003, XP, Windows 7, 8 and Vista.