Symbol 5490 from IEC 60417 - Title/Meaning: Enlargement of the cooking zone, concentric Function/description: To identify an indicating or control element for the concentric enlargement of a round cooking zone.
Additional information: 
Published in: Supplement O, 1996,3C/295/DIS
Own work using: iso.org/obp/graphics/grs/008a07fa-9341-473b-8f40-a5e7c1e88dac 200.png
Vectorization:  Mrmw