This strap end is based on several finds from Gotland, Norway, Gnezdovo, and others, dating back to around the 10th century.
It fits a strap that is at least 14 mm wide. It’s not an issue if the buckle is slightly wider, as it’s perfectly fine to narrow the leather at the end of the belt. Up to 25 mm width is acceptable. The key is that the leather is at least 14 mm wide for the strap end to be attached.
The strap end is made of bronze.