Sony has already launched most of its high-end models like the Xperia Z2, so its trying to spice up the arrival of its mid-range Xperia T3 model by touting the design. It claims that the otherwise modest 720p, quad-core 1.4GHz model is the worlds slimmest 5.3-inch smartphone at 7mm thick. Thats a weirdly specific stat, since there are much thinner devices like this 5.5mm Gionee smartphone.