Used in armored liquid level gauges and rectangular sight windows on boilers and process vessels in applications where level indication is required, L.J. Star Ilmadur I-420 replacement gauge glass  is manufactured to mil spec. Made from a high-quality formula of borosilicate glass, it provides clarity, high-pressure capability and chemical- and thermal-shock resistance. The glass comes in 3 styles: reflex glass with grooves that make it easier to read water levels; groove-less, non-tinted transparent glass; and high-pressure glass with up to a 0.002 flatness tolerance.

L.J. Star Incorporated; 330-405-3040; www.ljstar.com