Baby your neck and back. Use as wide a neckstrap as you can find. Maybe check out a shoulder harness. I use a Ray Hyman supersling to which I added the padded section of a neo-tech strap. Baris weigh 12 pounds plus and a thin strap like a regular Ray Hyman tenor strap can cut into your neck and cause nerve damage. This is easily avoided with a thick padded strap or a shoulder harness.