After being shocked at how much "proper" skinfold calipers cost, I was happy to find this one. I didn't expect too much as you usually get what you pay for. But to my pleasant surprise, this thing works well and is very repeatable. I've compared it to using the much more expensive Harpenden calipers and the results are pretty close. The Slim Guide might even be slightly easier to use and more comfortable for the client because the tips of the calipers are a bit wider. If you want a skinfold caliper to get you in the fitness or body composition appraisal game, don't hesitate to get this one. There's a real good chance you'll end up with the same body composition results with these as you would with calipers that cost 10-20x as much. When accuracy isn't a matter of life or death, it's okay to save a few bucks. And this was great bang for the buck.