The Keysight 85131C is an 81 cm long, semi-rigid RF cable with an NMD 3.5 mm connector (female) on the test port side and a PSC 3.5 mm connector (female) on the DUT side, designed for the frequency range from DC to 26.5 GHz. It offers an insertion loss of ≤ 0.43 × √f + 0.3 dB (f in GHz) and a return loss of ≥ 15.94 dB, making it ideal for precise high frequency measurements with Keysight network analyzers.