1.Kp/Inf.Ers.Btl.53 Erkennungsmarke

The tag or 'Erkennungsmarke' shows normal signs of wear. It belonged to a soldier who was drafted in the 1.Kompanie Infanterie Ersatz Bataillon 53 was formed in the summer of 1939  in Naumburg. It trained and supplied soldiers for Infanterie Regiment 53 which was part of the 14.Infanterie-Division. This division, and her units, saw their first combat during the invasion of Poland in September 1939. After Poland it participated in the invasion of Belgium and then Russia. 

In November 1942 the bataillon was renamed into Grenadier Ersatz Bataillon (motorisiert) 53, but the motorized aspact was dropped in July 1943. 
In 1944, by then it was Grenadier-Ersatz- und Ausbildungs-Bataillon 53, trained and supplied soldiers for Grenadier Regiment 425, 465 and 475. In April 1945 the bataillon was mobilized as Grenadier Ausbildungs Bataillon 53 and became part of the 463.Ausbildungs-Division which fell under the 4.Panzerarmee.
The 'O' on both parts of the tag stands for the soldier's bloodtype.