We have 2 black metal buckles.  They are both vintage items.   They do not quite match as 1 is rounded on the corners the other is more square cut.  They may have been for shoes.  They measure about 7/8" x 7/8" (the square one) and the other is about 3/4" x 1".  They are in nice condition.

2 Black Metal Buckles Vintage

$8.95Price