The MB663 Series has a new user friendly screw-less design. User can just plug in the hard drive and play. The MB663UB series is a slim, ultra-portable design that allows you to take your data with you wherever you go. This new generation 2.5" external enclosure was designed with the user in mind by not only allowing data mobility, but also quick screw-less installation for simple installation and maintenance. The MB663UB also utilizes the USB 2.0 interface so that you will be able to access your data through any computer without sacrificing speed.