Purchase very necessary, since this is a use of backup security on internal HDD, and very satisfying, since this simple driver practically not heated, is extremely silent, absolutely not bulky (barely the size a small portfolio), with a beautiful blue LED lighting from underneath the object, so in indirect and without glare, even in the dark, gets under way as soon as you own the computer and lights s 'off with him. At installation (quick and easy) it proposes to choose the books on which practice the backups (emails, web pages, doc etc.), choice of course always revisable. Backups are done without any difficulty. Supplied with a USB power Y-cable (for a second power by USB reinforcement possibly); taken firm without being harsh, taken strong and durable, should we say, a bit short cable (50cm for the longest branch, 25cm for the other), but it is not disturbing in the context of use with Laptop, so close to the machine.Excellent device sublime quality / price (purchased from a merchant market instead Amazon)