12./Inf.Rgt.15(mot) Erkennungsmarke

The tag or 'Erkennungsmarke' shows overall normal signs of wear. It belonged to a soldier who served in the 12.Kompanie Infanterie Regiment 15 (motorisiert). This regiment was formed in 1921 as the 15.Infanterieregiment as part of the 100.000 soldier strong Reichswehr army. In October 1935 it was renamed into Infanterie Regiment 15 and became part of the 29.Infanterie-Division. In the autumn of 1937 it became a motorized regiment. 
As part of this division the regiment saw it's first combat during the invasion of Poland. After that it participated in the invasion of France which took place in May 1940. From June 1941 onwards it operated on the eastern front and fought in areas like Minsk, Smolensk, Tula, Oral and Stalingrad were it was destroyed. 
In March 1943 a new regiment was formed known as Grenadier Regiment 15 and now operated in Italy untill the end of the war. 
The 'A' on both parts of the tag stands for the soldiers bloodtype. 

We have a nice soldier's handbook which is related to the same regiment here