Well, the half round thumb thing is a fake wheel - it can't rotate. Millimeters are easy to read, inches are less easy. The knurled knob to hold a reading works. The marks are engraved and accurate - the vernier reading scales came adjusted correctly. The jaw faces meet neatly with no light showing through. The only moving parts are the slide and the set screw. The fake fine adjustment wheel is also on the $85 Starrett https://www.amazon.com/Starrett-125MEA-6-150-Stainless-Resolution/dp/B000VDZEAC/ref=sr_1_1?ie=UTF8&qid=1541450139&sr=8-1 which is a "nicer" (also made in China) vernier caliper.