Symbol 1860B from ISO 7000 - Title/Meaning: Ventilation air flow, defrost and lower air outlet Function/description: To identify the control that allows air to flow from both the defrost and lower air outlets. To indicate that air is flowing from both the defrost and lower air outlets.
Additional information: 
On road vehicles: arrow may be coloured blue to denote cool air or red to denote heated air.
Own work using: iso.org/obp/graphics/grs/99a17774-c728-497b-add0-d9bf7a0f6ae8 200.png
Vectorization:  Mrmw