Nachrzg. Aufkl.Abt.(mot.) 4 EKM (4.Inf.-Div.)

The tag or 'Erkennungsmarke' shows overall normal signs of wear. It belonged to a soldier who served within the Nachrichtenzug Aufklärungs Abteilung 4. This abteilung was formed in August 1939 in Torgau from Kavallerie Regiment 10 and was part of the 4.Infanterie-Division. The division and her unit were put into action during the invasion of Poland in September 1939. In May 1940 it participated in the invaison of France by pushing through Belgium. 
In mid August 1940 the 4.Infanterie-Division became the 14.Panzer-Division and Aufklärungs Abteilung 4 was renamed into Panzer Aufklärungs Abteilung 40. It was put into action during the invasion of Russia and saw combat in areas like Cholm, Don, Mius and Stalingrad were (in February 1943) the division and her unit were destroyed. In May 1942 Panzer Aufklärungs Abteilung 40 was disbanned and the remnants were absorbed by Kradschützen Bataillon 64.
The 'A' on both parts of the tag stands for the soldier's bloodtype. 

Note the piece of bandage that was used as a neckcord.