Serial ports on USB allow further use of existing devices, even when the computer doesn't offer serial ports. The high speed serial port with the 128 byte transmit FIFO & 384 byte receive FIFO allow high speed communication, even in heavy loaded systems. Unique features reduce the system load. The serial port also allows unusual speed settings up to 921Kb with support to non standard Baud rates. As well the ports are protected with 2000V DC optical isolation and 25KV ESD surge protection. For more details on product, Please refer to http://www.papyrus.co.il/2_port_rs-232_usb_to_serial_adapter_optica_metal.htm