This is a Tag der Arbeit 1933 badge, from the NSBO (Nationalsozialistische Betriebszellenorganisation). It is from even before the regular Tag der Arbeit badges series that started from 1934 onwards till 1939.
A little background:
The first may 1933 was known as national labour day in the time of national socialism. Since 1934, the celebrations of 1 may became the national day of the German people. The Nazi party had declared 1 may a statutory holiday and nationally reinterpreted the previous day of the international working class as a recognition of all workers. From the outset, the celebration of may 1, 1933, was connected with the breaking up of the free trade unions – so, the Union houses were occupied by NSBO, the SA and the SS on 2 May 1933.
This is a badge in great condition, complete with functional needle and with a lot of history behind it. It should belong in every serious Tag der Arbeit collection.