Symbol 5068 from IEC 60417 - Title/Meaning: Horizontal linearity Function/description: To identify the control for the horizontal linearity, e.g. for a television receiver, a monitor, an oscilloscope.
Additional information: 
Published in: First edition, 1973
Own work using: iso.org/obp/graphics/grs/e3fd35f3-b650-47bd-8136-82fd75839e36 200.png
Vectorization:  Mrmw