Seba Micro Buckle, sometimes called a Spyder buckle, this buckle will suit most Seba models that use a Micro Buckle on their powerstrap, like the FR 1, High, High Light and Trix etc.
More of these buckles are held into place with a screw and t-nut, but if the buckle you want to replace is riveted on, you will need to drill out the original rivet and use a screw and t-nut (sold separately) to fit the new buckle.
Sold as a set of 2.