The part number is WX482.  It is a wireless antenna. [URL] [URL] Your installation DVD contains only the OS, and any drivers that are native to Windows (included by Microsoft).  Any drivers not included by Microsoft with the Windows OS need to be installed.  Looking at your 435, if you are installing Windows 7, you should not need to install System Software (Dell software that can change the functionality or identification of some of the hardware) or the chipset (neither are listed).  You'll then need video and possibly audio or modem drivers.  If installing Vista, you won't need the System Software (none is listed for this system), but you will need to start with the chipset drivers.
No tech support can tell me what this is and cant find it online so I am hoping someone here an tell me. My PC is a Studio XPS 435MT running vista sp2. The thing plugs into the back and it looks like the wireless card. Any help would be great thanks. [IMAGE]
Help to ID this Product that plugs in the back and in the wireless card I 
believe.