caliper as far as I can tell is fine. Measurements on blocks 3-2-1 show accuracy. The case needs improvement. The case comes with documents, a screwdriver, a spare battery and of course calipers. I am happy to keep any documents that come with the tool. 1) Through a slot inside the case in the top half, one could insert documents into the storage case. 2) The case could also be improved by making a slot for a screwdriver. and an appropriately sized battery for each to fit in their respective slots. 3) Finally, on the calipers near each button I would print the assignment of the button i.e. "on./off", "zero", "fractions/mm/inches". Buttons or in the same locations as similar calipers, but even on lower-priced calipers, have the function printed on the caliper.