Symbol 1659 from ISO 7000 - Title/Meaning: Service indicator; read technical manual 
Function/description: To indicate that a machine or equipment requires service. To indicate that the technical manual shall be consulted. To identify the location where the technical manual is stored.
Own work using: iso.org/obp/graphics/grs/31b32ef3-c276-469d-9b65-06fd47b4b2a2 200.png
Vectorization:  Mrmw