Shoulder Boards for the "Reichsfinanzdienst Zollgrenzschutz". The rank is Zollbetriebsassistent (green strip at the base of the Boards indicates a candidate for promotion to the next higher rank). If you look closely, you can see they are a very slight mismatch.

As gleaned from a forum discussion:

The Zollgrenzschutz belonged to the ministry of finance and had to protect the border against smuggle and illegal crossing, furthermore they had to observe the area. During the war, the ZGS continued with that, but soon became part of the military defence, fought against partisans and so on.