SM4931 is an SMA female-to-female RF adapter from Fairview Microwave designed to enable connections between two SMA female connectors. The adapter features a gold-plated stainless steel body with beryllium copper contacts plated to MIL-G-45204 specifications, providing excellent electrical performance with a maximum VSWR of 1.2:1 across its frequency range. Operating from DC to 18 GHz, the adapter meets MIL-STD-348 interface specifications and maintains an insulation resistance of 5,000 MOhms, with a maximum operating voltage of 500 Vrms AC and dielectric withstand voltage of 1,500 Vrms AC. The adapter measures 0.875 inches (22.2 mm) in length and 0.27 inches (6.86 mm) in width, weighing 4.9 grams, and operates reliably across a temperature range of -65°C to +165°C. Common applications include general-purpose RF testing, connector protection on expensive equipment, and high-cycle connection scenarios where the adapter can serve as a replaceable connector saver.