WD 500GB Elements Portable External Hard Drive  - USB 3.0  - WDBUZG5000ABK-NESN Ultra-fast USB 3.0 data transfers.Massive capacity - 500 GB For Mac compatibility this Hard Drive requires reformatting. Refer to Application Guide for guidance on this Free trial of WD SmartWare Pro auto and cloud backup software 1-year limited warranty WD quality and reliability