Symbol 3412 from ISO 7000 - Title/Meaning: Engine rotational speed, increase/decrease Function/description: To identify the control that increases or decreases the engine rotational speed by switching between two specified values.
pay attention to orientation of symbolAdditional information: 
Fonts shown are not restrictive.
Own work using: iso.org/obp/graphics/grs/affe304a-5f48-4329-8aa1-9c147da49c80 200.png
Vectorization:  Mrmw