I bought this to measure bearings whilst rebuilding my 600hp engine. I wanted to make sure everything is correct. And to my surprise, with 2 cam bearings, my Clevite bearings were 0.001" smaller. This saved my engine about $20,000 and a lot of headaches so don't be stingy and say it's overpriced. However, I installed a bearing and when I saw that I had no play with a caliper I used it to measure the bad bearings.