Ultrathin comes in two color options: one matches Space Gray iPads, the other, Silver. It’s only about 0.25” thick and weighs less than 0.71 pounds. That means when it’s attached to an iPad Air, it comes just shy of doubling the depth, and only adds a little over 70 percent to the weight. It feels like even less than that in use. The outside of the lid, which serves as the underside in typing mode, is a sheet of flat metal, with…
