Review on Fowler 52 646 100: Optimal Measuring Graduation Interval for Precise Accuracy by Alex Gilbert

Update to original review below: Engine runs. I received and tried the tool a few days ago and am happy with it. Good reproducibility and it seems to measure correctly as a "comparator" based on some cross-checks I've done. So while this inexpensive gauge (below) is not suitable for MODERN engines, another Fowler gauge, 52-646-500, will do. Of course if you're in the 1%, buy a Mitutoyo sensor, but I guess people in the 1% don't rebuild their own engines (LOL). It would be nice if Fowler or Revane were upfront and honest and OPEN in advertising that this sensor's accuracy is only plus or minus 0.0009 inches and repeatability is only guaranteed to within plus or minus 0.0004 inches of what these are "Measurement" essentially constitutes. Tool useless for any real precision work on a modern engine where the tolerance from the norm is say 0.0004! Yesterday I received the goods in the mail, today I returned them. It should not be sold for precise work. Had it been OPENLY disclosed in clear ENGLISH that the error was so large, I would have been warned that it was unsuitable for my intended use and all the loss of sending back and forth could have been avoided. These manufacturers and their representatives should make every effort to DISCLOSURE RELEVANT facts about the product and I should not play games to find data. This result is frankly common and one of the reasons this country sucks. When measuring an engine cylinder, you definitely need a gauge with an overall accuracy that is much, much better than the 0.0009 inch, which Fowler WISHED doesn't reveal until the product is actually in your mailbox, and at that time it is already too late .