German  Metal end for canvas straps.  This is a two piece metal stamped steel end for the Tropical and canvas straps used on all sorts of items, including canteen and mess kit straps, Rucksack straps, vehicle straps, etc.  These crimp onto the end of the strap to allow it to slide into a clip or ring or buckle without catching the material.  A pair of plyers is all that's needed to crimp them onto a strap.  Size is 3/4 inches wide.  Some straps are 1 inch. These might fit if you bunch the end a bit for the smaller end cap. I have seen it done before.