Gencon All In 1 Clip To Collar gently helps to control the most excitable strong dogs. When a dog pulls, both loops tighten and restrict the whole head, the dog backs off from the restriction and stops pulling. Only gentle pressure is needed to stop your dog from pulling. Does not ride up into eyes . Made for walking your dog on the left. One size fits all! Ideal for agility & flyball training and competitions. Trigger Clip on end of lead to connect the lead to your dog's collar for extra security.