WD 4TB Black My Passport Ultra Portable External Hard Drive - USB 3.0 - WDBBKD0040BBK-NESN [Old Model] Secure portable storage with up to 4TB capacity Password protection and 256-bit hardware encryption Automatic, local and cloud backup Stylish design with a range of exciting colors System Requirements: Formatted NTFS for Windows 10, Windows 8 or Windows 7 Requires reformatting for Mac OS X or other operating systems