Serial converter to add RS232C serial port via USB. Even if your computer does not have a DB9M connector, you can use the free USB port to connect your DB9 RS232C serial device to your laptop/desktop computer, such as Mac®, Windows, etc. Unlike regular USB to serial converter cables where conversion is done at DB9 end, the ICUSB232SM3 provided by StarTech.com is equipped with a converter chip on the USB end. The USB source conversion overcomes the technical limits of the 4.5m USB cable and allows you to connect it to a serial DB-9 extension cable with longer distance if needed (up to 15.0m depending on your application). Easy to install and easy to use, this USB to Serial Adapter is a cost effective solution to solve the compatibility problem of the latest computers and legacy serial peripherals. StarTech.com offers lifetime **and free technical support.