Symbol 5478 from IEC 60417 - Title/Meaning: Page enlargement Function/description: To identify the control for page enlargement on a display unit, for instance a teletext page.
Additional information: 
The triangles may be filled in
Published in: Supplement M, 1994
Own work using: iso.org/obp/graphics/grs/5ac18bdd-9a32-494d-8c7c-b6d91c00cb03 200.png
Vectorization:  Mrmw