Symbol 5057 from IEC 60417 - Title/Meaning: Contrast Function/description: To identify the contrast control, for example of a television receiver, a monitor or an oscilloscope.
Additional information: 
Published in: First edition, 1973
Own work using: iso.org/obp/graphics/grs/2b69ac35-8983-4d64-b8e6-eaf9a274334c 200.png
Vectorization:  Mrmw