Add an RS232 serial port to your laptop or desktop computer through USB The converter chip on the USB end of the cable allows extension of the DB9 serial over much greater distances than USB extension Drawing power from the USB bus saves the hassle of carrying an external power adapter for this add-on serial port Extensive list of compatible operating systems makes this device perfect for almost any RS232 application The ICUSB232SM3 3ft USB to Serial Adapter Cable lets you connect DB9 RS232 serial devices to your Mac® or PC laptop or desktop computer through an available USB port, as though the computer offered an onboard DB9M connector. Unlike typical USB to serial converter cables where the conversion takes place at the DB9 end, the StarTech.com ICUSB232SM3 features a converter chip on the USB end. Converting at the USB source overcomes the 15ft. technical limit of USB cables, allowing for a much greater serial DB-9 extension cable (50ft.+ is possible depending on the application) if necessary. Simple to install and use, this USB to Serial adapter is a cost-effective solution that bridges the compatibility gap between modern computers and legacy serial peripherals. Backed by a StarTech.com lifetime warranty and free lifetime technical support. What’s in the box USB to Serial Converter Driver CD User Manual