This is a very nice WWII German Wehrmacht Luftwaffe (Air Force) EM (enlisted man) or NCO (Non-Commissioned Officer) Belt Buckle.  Luftwaffe Belt Buckle (Koppelschloß). Originally the EM/NCO’s buckles were produced with a silver finish. This version was introduced around mid-1940, and a tropical olive drab version was introduced in late 1940. The colored finish was determined by regulations depending on what form of uniform it was to be worn with. This is a nice 2-piece alluminium construction parade style box buckle with a pebbled background, the separate frontplate is attached with four prongs. The buckle is not visible maker marked. Nice original Luftwaffe parade style buckle in very good condition!