A martingale collar is a special type of collar that helps a dog stay comfortable while being completely secure on a leash. A martingale collar is designed with two loops. The large loop is placed around the dogs neck and adjusted to fit. The leash is then clipped to the D-ring on the small control loop of the martingale collar. With the leash attached, the martingale collar gently tightens, If the dog tries to pull their head out of the martingale collar, the tension on the leash pulls the small loop taut, which makes the large loop smaller and tighter on the neck-- preventing escape. When adjusted properly the dog is never choked, but the martingale collar stays snug around the dog's neck. The martingale collar allows the dog to wear a comfortably loose collar that is only tight when it needs to be.