Remove Open A New Tab Button On Firefox Toolbar

How do i remove the Open a new tab button from the firefox tab toolbar?

Seen in the attached image:

I tried searching google and the forum, but have had no luck.

Thanks in advance

i think that's a TMP option. look around in there.

Right click - Customize - Drag

i thought that was an extension, go to extensions and disable "new tab button" or something that looks similar by right clicking>disable