Allows you to add a RS-422 / RS-485 port by connecting to a simple USB port ( 1.1 / 2.0 / 3.0 Compatible ) RS422/485 signals RS422 TxD+/-, RxD+/-, RTS+/-, CTS+/-, GND, RS485 Data+/-, GND Baud Rate from 300bps up to 921.6Kbps supported Transmit(TxD) and Receive(RxD) LEDS on unit for visual reference OS Compatibility:Windows 98, Me, XP, 2000, 2003, CE, Vista, Windows 7, and Windows 8 as well as Linux and Mac OS 10.X