This part of IEC 61169 standardizes the interface and ratings of the type 1.85 r.f. connectors of 50 Ω impedance and having a screw coupling mechanism. These connectors can be intermated with other 1,85 mm and 2.4 mm connectors. These connectors are recommended for use with semi-rigid and flexible cable and in microwave applications requiring high performance. These connectors have an operating frequency range of up to 65 GHz.