Model; U4 Mini Aluminum ATX Case Dear customer, U4 is launched at the end of 2016, the outer shell is made from 2.0mm aluminum magnesium alloy, with Jonson team’s accumulated experience of wire drawing anode surface processing craft from many years, the design style goes on with the sense of simplicity, simple streamline and strong metallic. By using outer aluminum and inner steel with innovative structural joining technology, it perfectly fuses the strong structure and good appearance of the product.