M.G.K.zbv Gren.Ers.Btl.484 Erkennugsmarke

The dog tag or 'Erkennungsmarke' shows signs of wear. The soldier of the tag served in the MG.Kompanie z.b.V.Grenadier Bataillon 484. The bataillon was formed in November 1939 as Infanterie Ersatz Bataillon 484. This bataillon trained and supplied soldiers for the 254.Infanterie-Division. In November the bataillon was renamed in to Grenadier Ersatz Bataillon 484. In May 1944 the ersatz bataillon was disbanned and the soldier were absorbed in Ersatz- und Ausbildungs-Bataillon (M) 276. 
In March 1945 this bataillon was moved to Denmark where it became part of the 233.Reserve Panzer Division. In late March the bataillon was used to replace parts of Grenadier Regiment 590 which was part of the 328.Infanterie Division. In April 1945 the bataillon was deployed in the Kolding area. 
The 'A' on both parts of the tag stands for the soldiers bloodtype. 
Interesting EKM.