Most brands will have a measurement from smallest to largest. This one is 15" - 23" Measure your dog around the chest right behind the front legs. I advise getting a harness where the largest measurement is a few inches larger than your dogs measurement so then the harness can be adjusted a little either way to fit your dog properly. Hope that helps. :)
Sorry, there is no list on the back. Judging by the size, and because it does have some adjustment, I would guess it would fit a small to medium size dog. Definitely not something like a large german shepard or husky.