3.5 mm connector
3.5 mm connectors are precision coaxial microwave connectors that look similar to SMA connectors but use air dielectric and work at higher frequencies than SMA, up to about 26 GHz. They will mate with SMA. Special care needs to be used not to rotate the connector after mating, and manufacturers recommend the use of torque-limiting wrenches for fastening.
See also 2.92 mm connector.