Leather is smooth against a dog's neck and will not pull hair like a lot of nylon collars. This also helps the collar rotate around your dog's neck when you cue with a checkcord, thus maintaining a consistent point of contact. The hardware is solid brass and you can feel confident it is not going to pull apart when your dog puts pressure on it. The extended D-ring makes it easier to attach a snap to the collar.  This collar is 21 inches long and has 8 holes for the perfect fit on your dog. This collar is approx. 1/8 inch thick.