What is a DMG file and how do I install a driver from it?
Files with the .dmg extension are compressed disk archives or folders that
make downloading a complete set of files more easy. Under Mac OS X often you
download a driver as a simple file with .dmg extension. Such files are not used
Files with .dmg extension are normally opened automatically after downloading.
If not, simply clicking on it in Finder will open the archive automatically.
After opening the file, you can proceed with the driver installation by following
the instructions in the manual of the product or the readme file for the download.