Tripp Lite Keyspan High-Speed 4-Port RS232 Serial DB9 to USB Adapter Hub(USA-49WG) Connector 1 4x DB9 Serial Plug &amp; Play: Appear as standard COM ports Bus Powered: No external power adapter required Serial Adapter allows up to four serial devices to be connected to a single USB computer Plug-and-play convenienceDB9 serial ports are seen as COM ports by your computer, and are available for use by any program that accesses COM ports No need for an external power adapterdraws power directly from your computer via the USB connection DB9 serial ports support data transfer rates up to 460 Kbpsfour times the speed of a standard built-in serial port DB9 serial ports support data transfer rates up to 460 Kbpsfour times the speed of a standard built-in serial port