Hey, so I'm a newbie when it comes to hard drives and would've thought that you just plug it in and start using it... wrong.
With the Mac, you must reformat the hard drive so that it's compatible with your laptop - in this case, your Mac.
All you do is open 'Disk Utility' in your apps area, then locate to your hard drive on the left hand side and click on the name of the hard drive, then click 'erase' on the right hand side and click the 'Format' button which you should change to 'Mac OSX (External Journaled)', then click Erase.
TADAA!! Your hard drive will now work.
As for the product itself, I bought this for my dad to transfer some movies and shows over and DAYUMMMM this thing transfer stuff over pretty damn fast.
I love this, I'm going to buy another one very, very soon.
Don't hesitate to get this - it's awesome.
If you're a mac user and this helped you, please thumbs up so that other people can see this (others who are newbies like I was. lol)