Symbol 6298 from IEC 60417 - Title/Meaning: Electrotechnical protection, general Function/description: To indicate the provision of protection, shield or guard against/from unwanted disturbance and/or environment.
Additional information: 
See also ISO 7000-2410.
Own work using: iso.org/obp/graphics/grs/312c7554-35ab-462c-bd92-03a2cf959c10 200.png
Vectorization:  Mrmw