This Sterling Silver Belt buckle by Blackinton measures about 1 3/4 inch in length and 1 5/8 inch at its widest point. It is made for a1 inch belt. I think this one is actually old store inventory, never worn. It has some shop wear, minor surface scratching. A good buffing would restore it to like new finish.
The piece is marked "Sterling", with the Blackinton mark and the style number, which appears to be 2795. The buckle weighs about 26 grams.
I have the same basic buckle with a slightly different closure mechanism listed, Sterling Silver Belt Buckle by Blackinton 1043.
Sterling Silver Belt Buckle by Blackinton 2795