ExpressCard providing two RS422/485 serial ports. ExpressCard is 34mm wide and fits 34mm or 54mm slots. Data transfer rates up to 921,600 baud rates and the 128 byte deep transmit and 384 byte receive FIFOS, coupled with 1Mbit/s line drivers deliver uncompromising performance on your laptop. Drivers for Windows 32 bit and 64 bit Operating Systems including Windows XP, Server 2003, Vista, Server 2008, Windows 7 and Windows 8.