2021DIN EN 352-4:2021 Hearing protectors - Safety requirements - Part 4: Level-dependent earmuffs; German version EN 352-4:2020
1970DIN EN 352-4 E:2017-07 Hearing protectors - Safety requirements - Part 4: Level-dependent earmuffs
2006DIN EN 352-4:2006 Hearing protectors - Safety requirements and testing - Part 4: Level-dependent ear-muffs; English version of DIN EN 352-4:2001 + A1:2005