I needed something like this for a long time finally broke and got it. Digital calipers are a must for measuring and measuring small units with precision. I've borrowed one from a friend a few times and I've used it enough times to know its value and how to use it properly. This one works well out of the box, it comes with instructions but is so intuitive that it's not really needed. Mine was already programmed in imperial units, but it just switches to metric with a single button. Another great feature is that you can set the starting point to zero at any point. So if you need to measure something that you can't access from both sides, you can make this work. This tool is well made, high quality, feels solid and heavy in my hand, and snaps well to ensure accurate measurements.