UNE-EN 61169-16
Radio-frequency connectors - Part 16: Sectional specification - RF coaxial connectors with inner diameter of outer conductor 7 mm (0,276 in) with screw coupling - Characteristic impedance 50 ohms (75 ohms) (type N) (IEC 61169-16:2006). (Endorsed by AENOR in August of 2007.)