Pathway MR Series systems utilize a serial port to connect their instrumemtation to a computer. Many new computers come standard with a USB port. Therefore, if you are having your computer system built, then you should request a serial port, if not, you need to get a USB to Serial Port Converter. The Keyspan USA-19HS USB Serial Adapter is the only USB to Serial Adapter that has been tested and proven compatible with Pathway’s instrumentation.