The U4 B; launched at the end of 2016 sport's an outer shell made from aluminum magnesium alloy 2.0 mm thick. Metallic, streamlined, and classy; the design style gives it a sense of industrial simplicity with purpose. By combining aluminum for the exterior and steel for the interior, it forms a perfect union of structural integrity and elegance. The U4 also displays a tempered glass panel for the left side plate. With edges cut by a CNC machine for precision accuracy with virtually no gap between the glass and metal frame. The U4's side glass panel is perfect for showcasing any hardware that has RGB lighting. Not only does it look good, it also serves to reduce more noise and vibrations than other typical traditional cases with metal side panels.