At ICL, we have been producing high quality crystal optics for use in infrared spectrometers, accessories, and other analytical devices since 1962. We are the only U.S. company that produces KBr crystal, a standard component of infrared spectrometers. In house, we also produce the materials for other vital crystal optics such as KCl, NaCl, AgCl, CdMnTe, and more. We also stock a large variety of spectroscopy optics made from other essentials like CaF2, BaF2, ZnS, ZnSe, Si, BK-7, etc. Circular Discs are available in all of the common sizes, typically in the range of 20mm-50mm (for use as windows common to infrared sample cells and accessories). However, we offer a large range of sizes for various applications, from tiny plugs for microscope slides to large aperture optical viewports (100mm in diameter or more).