Symbol 5078 from IEC 60417 - Title/Meaning: Stereophonic headphones Function/description: To identify the socket, terminals or switch for stereophonic headphones.
Additional information: 
Published in: First edition, 1973
Own work using: iso.org/obp/graphics/grs/b197d307-7877-4b75-ae76-3e0c14048fa1 200.png
Vectorization:  Mrmw