Our Adjustable Nylon Harness is built with strong 1‚Äù-wide nylon webbing for lasting comfortable security for your dog. The adjustment sliders and buckle are durable, impact resistant acetate, and the O-rings are rustproof solid brass. If your dog pulls on the leash, the tension gets distributed across the shoulders and chest rather than the neck and throat. Fits dogs with chest circumference: S—16‚Äù-20‚Äù, M—18‚Äù-24‚Äù, L—21—32‚Äù, XL—27-43‚Äù.