You can find it here: http://magellan.cachefly.net/manuals/MRM_300na_en.pdf
You may also want to know that there is a MAJOR firmware update avaiable for your device.. It looks like it would make your GPS a lot faster and more accurate. You may want to take care of that update too while you're working on your device. The update can be found here: http://www.magellangps.com/support/notes.asp?supportID=288
Answers & Comments
You can find it here: http://magellan.cachefly.net/manuals/MRM_300na_en.pdf
You may also want to know that there is a MAJOR firmware update avaiable for your device.. It looks like it would make your GPS a lot faster and more accurate. You may want to take care of that update too while you're working on your device. The update can be found here: http://www.magellangps.com/support/notes.asp?supportID=288
Let me know if that helps!
Regards,
Steve