Garbage. If I had written this review 9 months ago when I received it I may have given it 4 or 5 stars. I only used it once to completely backup my MacBook Pro as a clone. As far as I could tell everything went well and seemed normal. 9 Months lated I pull it off the shelf and it won't boot and there appears to be nothing there. Luckily I'm not totally dependent on this backup. I guess it's going in the garbage where it belongs.