Jonsbo team has been trying to provide users with a solid material and moderate price ATX full aluminum shell case, limited by the high cost of aluminum we have not been able to achieve this desire. The rapid popularization and reducing price of SSD bring us the opportunity for the development of U4, by reducing the amount of 3.5 HDD support and cancelling the optical drive rack, under condition that the compatibilities of high-end hardware are not affected, Jonsbo team has created a middle-level full aluminum ATX case for users. U4 can support 170mm height CPU radiator, 310mm length high-end display card and 120/240mm cooler. In materials, U4 keeps the same level with high-end case, 2mm thickness aluminum plate is used for the shell, 1.0mm SGCC steel plate is used for the structure, and 5mm thickness full tempered glass is used for transparent side plate, good materials used and reasonable structure design makes U4 a slightly small but with solid structure and reasonable expansibility full aluminum light effect showing case. U4 is launched at the end of 2016, the outer shell is made from 2.0mm aluminum magnesium alloy, with Jonsbo team's accumulated experience of wiredrawing 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. U4 makes use of full tempered glass for side plate and CNC machine to cut the edge accurately, so the gap between them can be controlled precisely and the edges are smooth which will not hurt our hands. Full tempered glass side plate does not only provide wide-angle display for illuminated hardware but also bring a better solution for isolating noise and reducing resonance than traditional case with metal side plate.