The Word Mac Compatible could be misleading… One thing is Mac compatible and another thing is formatted for Mac.
There are certain revisions of Mac OS X that will not support some drives. However, must drives will work once formatted for Mac.
AFAIK this one will work with OS X 10.4 , 10.5 and 10.6.
You can format the drive with the steps provided on this article : How to Format
If you connect the drive to the Mac you will be able to read but not write files due to the file system. Formatting will allow you to convert to a Mac compatible file system, but you can get an application that will allow you to write to drive the way it is right now.
