This model is based on several English finds from the 14th century. It is designed for a belt that is at least 15 mm wide, but larger buckles are also compatible as the strap can be narrowed at the end. It works for belts with widths up to 25 mm. The key requirement is that the leather is at least 15 mm wide to attach the belt end.
The belt end is made of bronze.
See:
