I logged on Amazon.com and searched "Marble Macbook Cover." Once I got a long list of options I filtered them to see Macbook Air 13 inch only. Once I found covers that were perfectly fit for my laptop I started to click all of my best options to "Add To Cart."
Once I had about 4 or 5 different covers in my "Add To Cart" I went through and chose my favorite. Before checking out I triple checked that the cover was exactly for my laptop... there's nothing worse then ordering something for your computer and it turns out it's the wrong size.
Below are two photos of the cover I purchased for my laptop, I've only had it for about two weeks and I'm already in love!