Built-in 12TB Capacity USB 3.0 External Hard Drive (Estimate 16TB capacity available after formatted) Works for any WIndows OS Desktop PC, Laptop with USB 3.0 Port Expand computer hard drive storage instantly! Add extra storage to your Desktop PC / Laptop Without opening up the case Perfect for hard drive expansion and backup storage for your entire Windows OS system! (Do it before it crash, you never know when it will happen! "Daily schedule backup is no longer optional" )