I have to say, I see the exact same style of caliper under a ton of different brands. I'm not sure if they are all the same product under a different label, or if they have quality or performance differences between them.
Measuring body fat is a more accurate way to track fitness or weight loss goals. It can be used in conjunction with body weight and other measurements to paint a more accurate picture than using body weight or BMI on their own (especially if you are athletic).
I'm happy to see that these come with instructions, which go into some very specific details on how to use the calipers, but it's not completely concise. I'd suggest supplementing the manual with online videos to get a better sense of how to use these.
The caliper is easy to use, however, some measurements may require a second person. For example, a common measuring point is by the shoulder blade, and that's just not an area you can measure yourself.
That said, these also don't have a "hold" option, so you'd need to be looking at the readout while pressing the skin fold with the calipers. The only device that I'm aware of that can "hold" the reading, are digital body fat calipers.
Does it work? Here's where it gets tricky...
Measuring body fat accurately would likely require a DEXA scan, and if you're using calipers, someone who's skilled at taking these measurements consistently.
Does accuracy matter? Depends on whom you ask! I find that as long as you're consistent in how you take measurements, you're still able to track progress reliably, and that has benefits.
At the time of this review, this body fat caliper is listed at $20.22, which is pretty reasonable for this style of caliper.