Seagate Expansion 2TB Desktop External Hard Drive USB 3.0 (STEB2000100) Easy and simple to use - simply plug in the power adapter and USB cable Fast file transfers with SuperSpeed USB 3.0 System Requirements : Windows 8, Windows 7 operating system. Compatible with USB 3.0 and USB 2.0 Drag and drop file saving for Windows, right out of the box Please note: For Mac compatibility this Hard Drive requires reformatting. Reformatting the drive will erase all content unless it is backed up to another drive. Refer to Application Guide for guidance on this.