PROVIDENCE, R.I., Feb. 4, 2015 — Custom fabricated sapphire viewports and sight windows for ultrahigh vacuum (UHV) systems and process machinery are available from Meller Optics Inc. The windows provide Moh 9 hardness and are suitable for applications from UHV to 10,000 psi and from cryogenic temperatures to 1,000 °C, depending on configuration. They resist chemicals (including fluorine to 300 °C) and most acids, and are impervious to fast-moving water and particulates such as blowing dirt and sand. Available in a variety of configurations and sizes from 0.25- to 10-in. in diameter and 0.5 mm to 1 in. thick, the windows can be fabricated with stepped edges and elliptical edge shaping, holes, slots and wedges for mounting, and include antireflection coatings.