... including Zygo interferometers, Perkin-Elmer Lambda 900, Radius tester, and Spectrometer ensure the quality. Our senior engineer can provide free ... Telecom) Materials:Glass, Fused Silica, Silicon, Ge, ZnSe, MgF2Standard SpecificationDig and Scratch: 60-40Center thickness tolerance: 0.03-0.4mmDiameter Tolerance ... feel free to contact us or our Canada office. Optical Lenses for Industry and R&D