Authentic Herm sprenger dog collar. XL 4mm, 30". 14 links. You can add or delete links to custom fit your dog. We bought a 24 " then bought extra links to fit our big dogs. Hence the extra 6 " from original 24". We also exchanged the quick release to a quick link . See pic #4. We did that because the quick release could break. To open and close collar just squeeze the link together to open then slip back in to close. It's a little tight by design. Pic # 6 is a stock photo