Coaxial line devices and systems are becoming more prevalent at frequencies above 18 GHz. This standard covers a precision pin and socket connector for use with 3,5 mm rigid precision coaxial lines so as to minimize test apparatus errors attributable to coaxial connectors. These connectors are constructed so as to affix on the 50 SI, 3,5 mm rigid precision coaxial line described in IEC 457-5, and to provide low reflection to 34 GHz. For mated pairs, a reflection factor of 0,003 + 0,00135f (GHz) is typical for GPC connectors. These connectors may be, and often are, mated with SMA connectors.