Review on 50mm Extender with 160MM Internal Indicator Resolution by Ben Demers

When I got this caliper the slow speed needle was stuck at 2. It's ok, I measured the bore. It seemed consistent, but not accurate enough to make later engine cylinder decisions with 0.0005 tolerances. For early engines that can endure. Option 001, it will help you. Depending on your needs, this may be sufficient for a disposable tool. I ended up returning it for a more accurate tool, but with precision comes a steep price increase. Seems well made and worth the money.