The Mitutoyo 178-390 detector is used with the Surftest SJ-210 and SJ-301 surface roughness testers, and has a diamond stylus tip, uses skid measurement detection, and comes in types such as standard or deep groove that have varying head sizes. The detector has diamond stylus tip material, and radius, for precision surface roughness detection. It uses skid measurement detection with skid force of 400mN, or less, and measuring forces such as 4mN (SJ-301), or 0.75mN (SJ-210). The detector connects with the Surftest drive unit for operation. A detector connects to a surface roughness tester, using a cable, to transport form measurement readings in metrology applications such as shop floor, machining, statistical processing, histogram-based data management, and quality control (QC).

Mitutoyo manufactures precision measuring tools, metrology equipment, and systems. The company was founded in Tokyo in 1934 and formed Mitutoyo America Corporation in 1963, which is headquartered in Aurora, IL.