This is made from Hermann Oak leather for my dog Liberty. She chewed through the other leash. It is 2 pieces of leather. 8-9oz. And 3-4oz. Glued and stitched.
By the look of it, probably indestructible 
It might get some signature teeth marks, though tough to imagine it tearing in any way. Very solid - and great leather color choice, wheel pattern on it, and clean stitching. That looks like one I’d want to get!
Great hardware choice, too. Makes me want to get crafting