Ordered a size Small, first glance I was sure it was too small. However, turns out it is a perfect fit for our 10 lb dog. It looks snug in photo but there is breathing space at every opening, comfortable fit for the dog. One caveat: a family member says our dog slipped out of this halter once but maybe the halter wasn’t fastened securely, I now make sure it is on as snug as possible and have had no problems. I also cannot vouch for this product on a heavier stronger dog. The clasp at top is plastic, very easy open and close function, and there is a sturdy layer of Velcro under the clasp that holds securely. The metal rings for the leash are sturdy. Very happy with this purchase.