Symbol 6004 from IEC 60417 - Title/Meaning: Door-phone Function/description: To indicate a reference to a door-phone.
Additional information: 
Published in: 3C/1536/CDV, 3C/1554/RVC
Own work using: iso.org/obp/graphics/grs/5b68e35f-5566-4a5c-a821-7f4118a10acd 200.png
Vectorization:  Mrmw