I think this device works but there are definitely many ways you can easily mess up when using it. You can take 5 measurements and 3 of them might be the same. You will have to take mulitiple measurements. Also many location of the belts are in an awkward location where you can barely get your hands on and this will also make proper measurement difficult. This tool can be good to give you an idea if you are close to your target. So bottom line is I would continue using it as it would give me a better idea of the tightness and better than the finger method.
