Winchester KINGS® brand SMA series RF connectors are semi-precision 3mm high-frequency subminiature connectors. They are characterized by a 1/4-36 mating thread and a butt mating outer contact. The SMA connector was originally conceived for .141-inch semi-rigid cable, but the concept has broadened to accommodate cables from .047-inch to .250-inch OD both semi-rigid and flexible. It provides repeatable electrical performance from 0 to 18 GHz and is widely used in microwave systems and subsystems where minimum attenuation and low VSWR are required. VSWR performance and high-frequency limit are dependent on the choice of cable and design of the connector. Semi-rigid cables have a frequency range of 0 to 18 GHz; flexible cables 0 to 12 GHz. SMA connectors are covered by MIL-PRF-39012. Items qualified to MIL-PRF-39012 appear in the latest QPL list for MIL-PRF-39012.