Harnesses in our Z Series are equipped with "bungee cord-like" elastic rubber straps. They absorb and mitigate the shocks resulting from sudden pulls and serve as a cushion for comfort between your hand and your dog. Constant pulling isn't something to be overlooked. It creates stress on you and your dog, especially on longer walks and outdoor activities. Consider our Z Series if you have an excited pup that constantly pulls. Why Lite Gear Z Harness? Different situation calls for different wears. You wouldn't wear jeans and sandals to a hike because that would just be uncomfortable, right?