Mitutoyo 157-904 Series 157 Optical Parallels, Range 25 - 50 mm, Set of 4 pcs

The Mitutoyo optical parallels are constructed of optical-grade glass and can measure the parallelism and flatness of a micrometer's measuring face.

Features:

• When used with a monochromatic light, a Mitutoyo optical parallel can determine the measuring surface parallelism within 0.2 µm / 0.000008" and flatness within 0.1 µm / 0.000004" on micrometers.
• Optical parallels are precision polished and lapped for exceptional flatness.
• Set of parallels consists of 4 thicknesses
• Constructed of highly polished, lapped optical-grade glass
• Inspects the flatness of metal, ceramic and other materials
• Supplied in a fitted wooden case