Review on Precision Measuring with Proster Calipers: Revolutionary Electronic Fractions Technology by Rolando Munoz

The picture shows that there must be a roller screw to move the caliper up and back. what I got didn't have it and didn't have space to put it - ie. he didn't fall down. I would have taken a picture but the box smelled of something like perfume and I was itching to wrap it up and let it go. I tried using it without the wheel and the slider moved easily enough, but the sharp edge on the back of the slider was very sharp and awkward to use. NOT FOR MEASURING SMALL GEMS - it is not designed for that. Blade tips are very sharp. and it is very difficult to grab small stones. It looked like I could lay it flat and measure it, but it's not flat on either side so I had no choice but to try and catch it with those sharp pinpoints. A previous review said it looked like cheap metal, but this one was heavy and certainly felt like stainless steel. I measured US pennies and nickels and it was pretty good (within 0.02mm). but it was difficult to tighten the top screw without moving the slider (it moves very easily). It's hard to let go of your hand to write down the result.