Part of the biochemical reaction arrows series.
<a href="//commons.wikimedia.org/wiki/User:GKFX" title="User:GKFX">GKFX</a><sup><a href="//commons.wikimedia.org/wiki/User_talk:GKFX" title="User talk:GKFX">talk</a></sup>
<a href="//commons.wikimedia.org/wiki/File:Biochem_reaction_arrow_reversible_YYNN_horiz_med.svg" title="File:Biochem reaction arrow reversible YYNN horiz med.svg">File:Biochem_reaction_arrow_reversible_YYNN_horiz_med.svg</a>, rotated.