The MacBook Pro Retina 15 'is very sensitive to vibrations (according to the store's Genius Bar). It's strange for a laptop but the danger is that its components are "welded" to the hull so no replacement of parts in case of problems. I had some alerts and he was recommended to invest in this shell. I travel by two wheels and my Mac is subjected to micro shocks and other vibrations. This cover is at the top because absorbs all! top quality!