I bought a sling years ago that has a very slight S shape. It's a double strap that is fairly wide where it rides on the shoulder. The strap meshes together with velcro so it can be used as a single strap, or it separates so you can use it like a back pack. I've loved it. it is very functional , even after many years of use. People I hunt with, like it and want one, but it has no identifying information on it. I have never seen another one like it, although I keep looking. Maybe someone out there has info on one like this.??