A differential pair flat cable includes a planar substrate, signal conductors, a shield conductor, and exposed signal connection pads. The cable also features a slot in the planar substrate and shield conductor, which receives a vertical shield tab of an inner shield terminal to provide mechanical retention and electrical grounding. A connector assembly mounts to the cable end, comprising an inner signal terminal, an inner shield terminal with a vertical tab, an insulative inner housing, and an outer shield terminal. The assembly provides a robust, low-loss connection suitable for high-speed data transmission, with improved signal integrity and electromagnetic compatibility. The design enables easy assembly and reliable performance, making it ideal for various applications, including automotive and industrial networking.