The step-in harness is made from the same high quality nylon as the collar and lead. It also has the reflective stitching for easy nighttime visibility. The contoured components makes it fit snugly and the double die-cast ring is attached to your lead. Adjusting the harness is easy, one side can be released a lot more than the other. When your big boy pulls, there is no pressure on his neck, it is all transferred to his back.