Kampfgeschwader z.B.V.1 Erkennungsmarke

The tag or 'Erkennungsmarke' shows overall signs of wear. It belonged to a soldier who served within the '1.Flughafen Betriebs Kompanie I.Gruppe Kampfgeschwader z.B.V.1'  This unit was formed in October 1937 as Kampfgruppe 1 from the IV.Gruppe Kampfgeschwader 152. It was equipped with the Junkers Ju52. In August 1939 it was renamed into Kampfgeschwader z.B.V.1 and enlarged with a total of 4 Gruppen. The I.Gruppe was put into action during the invasion of Poland. In April 1940 the I.Gruppe participated in the Norway and Denmark campaign and later during the invasion of the low countries. In 1941 the I.Gruppe and II.Gruppe was part of the Battle of Greece and in the summer of 1941 in Russia. In November 1942 it had the task of supplying the troops who fought in Stalingrad.  

Looking at the back of the tag we can see that the soldier first served in another unit. We have deciphered it and it says Flughafen Betriebs Kompanie Kampfgeschwader 152 which matches the fact that he served in the unit that became Kampfgruppe 1 and later Kampfgeschwader z.B.V.1.
A Betriebs-Kompanie is a unit that repairs and services the planes. 
The 'B' on both parts of the tag stands for the soldier's bloodtype.