One of the biggest issues with typical aluminum cases is their bulkiness: the original metal iPod cases were big, brick-like boxes that felt durable but threatened to make the devices inside unpocketable. Core?s Aluminum Sliders tackle that issue in a couple of ways, first by eliminating hinges in favor of a two-piece slide-together shell that locks into place on the sides, and then by using anodized aluminum that is just thick enough to be?