Some of the hard drive manufacturers market a 'Mac version' of their PC drive, but it costs a little more. A WD 500 GB drive is often sale-priced at $60. The easiest solution would be to purchase another WD Passport drive for use with your Mac and format it accordingly. Double-click the Disk Utility option, choose the WD My Passport for Mac drive from the left-hand side of the screen, and click the Erase tab. On your Mac computer, click the Finder icon and select the Applications option followed by the Utilities option.
To use this drive with macOS X, you have to format it.
