Add an rs232 serial port to your laptop or desktop computer through usbr r the converter chip on the usb end of the cable allows extension of the db9 serial over much greater distances than usb extensionr drawing power from the usb bus saves the hassle of carrying an external power adapter for this add on serial portr extensive list of compatible operating systems makes this device perfect for almost any rs232 applicationr r the icusb232sm3 3ft usb to serial adapter cable lets you connect db9 rs