2018DIN EN 60154-4:2018-04 Flanges for waveguides - Part 4: Relevant specifications for flanges for circular waveguides (IEC 60154-4:2017); German version EN 60154-4:2017
1970DIN EN 60154-4 E:2016-07 Flanges for waveguides - Part 4: Relevant specifications for flanges for circular waveguides