30Pcs Surface Roughness Comparators,Roughness Test Block Ra0.05-12.5mm Microfinish Comparator, Surface Finish Comparator Set for Lathe Machinery Manufactur Teach (30pcs Surface Roughness comparators)

Everything came well packaged, and the feeler gage set looks pretty solid. The four swatch holder has set screws along the edge that you can back off if you need to remove a sample for some reason. The samples themselves look to be well machined, but don't come with any sort of traceability, and I don't have an effective way to confidently verify their claimed accuracy. If you're a hobbyist on a budget these could be a good option, but if you need these for completing customer jobs I'd personally shell out the extra cash for something with a standard I could point to.

This set of comparators is a handy tool for quality control in my manufacturing business. It helps ensure that our products meet the highest standards.