INSTANT. ADD-ON STORAGEReliable. high-capacity storage for ultrafast data transfers.Massive CapacityWith up to 4TB capacity. there's plenty of room for all your important files and precious memories.Transfer Files FastConnect to the SuperSpeed USB 3.0 port and quickly access. save and transfer your files and HD Movies.Plug-and-Play SimplicityWorks right out of the box with Windows® PC. Just plug into the USB port to instantly add storage.USB 3.0 AND USB 2.0 COMPATIBILITYWith this single drive you get compatibility with the latest USB 3.0 devices and backward compatibility with USB 2.0 devices as well.WD QUALITY INSIDE AND OUTFor years. millions of people worldwide have trusted their data to WD hard drives. and our first concern is to reliably store that data. So we build the drive to our demanding requirements for durability. shock tolerance and long-term reliability.TECHNICAL SPECIFICATIONSFormatted NTFS for Windows 10. Windows 8. Windows 7. Requires reformatting for Mac OS X . Compatibility may vary depending on user's hardware configuration and operating system.