Abstract: A high speed transmission electrical connector (1) comprises a dielectric body (10), a plurality of signal contact units (30) and grounding contacts (20) alternately retained in the dielectric body. Each signal contact unit has a differential pair of upper and lower contacts (32, 34) separated from each other for transmitting differential signals between an electrical component and a circuit board. Each upper or lower contact comprises a retaining body (322, 342), a resilient beam (324, 344) and a soldering portion (328, 348) extending from opposite ends of the retaining body, respectively. The retaining body of the lower contact defines a cutout (340) in an upper side (341) thereof adjacent to the upper contact. The cutout is like an inverted funnel in cross section for eliminating electrical skew between the upper and lower contacts and therefore maintaining system impedance.