Seagate 4TB Backup Plus Portable (STHP4000403). Have space to grow. Looking for an external portable hard drive that’s reliable, stylish, and offers massive capacity? Meet Seagate® Backup Plus portable drive. With sleek colors to choose from and up to 5TB of serious space for a growing digital library, this portable HDD is compatible with USB 3.0 and both Windows and Mac computers. Topping it off—on-demand and customizable backup options that make file protection practically effortless.