Stamm Kp./Gren.Ers.Btl.1 Erkennungsmarke

The dog tag or 'Erkennungsmarke' shows signs of wear. The bataillon was formed in late August 1939 in Königsberg as Infanterie Ersatz Bataillon 1. It trained and supplied soldiers for Infanterie Regiment 1 which was part of the 1.Infanterie-Division. Besides this it also supplied soldiers that served within the 3.Armee and Feldkomandantur 195. In November 1942 the bataillon was renamed into Grenadier Ersatz Bataillon 1 and in February 1944 the bataillon became Grenadier Ersatz und Ausbildungs Bataillon 1. 

In October 1944 the bataillon trained and supplied soldiers for units that served under the 561.Volks-Grenadier-Division which fought in Königsberg and was destroyed in March 1945. In February 1945 Grenadier Ersatz u. Ausbilungs Bataillon 1 was destroyed in the Braunsberg area and the remnants were absorbed by Grenadier Ersatz Bataillon 47.

A Stammkompanie was a unit that trained the soldiers. Often the soldier of this kompanie were soldiers who had frontline experience, but no longer were fully usable at the front due to injuries. Of course this changed later in the war as there was a shortage of (front)soldiers and where mobilized also.
The 'A' on both parts of the tag stands for the soldier's bloodype.