Fig, 1. The correct way of putting on a slip-chain collar. Note that the links run from the ring attached to the leash, through the other ring, and continue over the top of the dog’s neck so that the collar loosens automatically when the leash is relaxed.

Fig, 2. The incorrect way of putting on a slip-chain collar. The links are going through the ring and underneath the dog’s neck. In this case the collar will not loosen when the leash is relaxed.