In gilt molded aluminum, measuring 49 mm x 63 mm, marked with the RZM (Reichszeugmeisterei) and maker marked "M4/39" (Richard Sieper & Söhne, Lüdenscheid) on the reverse, also marked 1 in centre (Angolia states this is for an unknown purpose), extremely fine. This particular buckle is illustrated on page 278 of "Belt Buckles & Brocades of the Third Reich, Revised Edition" by John R. Angolia and came from his personal collection.
Footnote: From the collection of approximately 900 German buckles accumulated by John R. Angolia, who start collecting buckles, belts and brocades from 1944 until around 1990; most of the buckles were obtained from the American and German veterans; most of these buckles present a core of Angolia’s book “Belt Buckles & Brocades of the Third Reich”, published in 2001.