C Range Infrared Window With Kwik Twist, Size: 4 IN, Viewing Aperture Diameter: 89 MM, Viewing Aperture Area: 6322 SQ-MM, Thickness: 2 MM, Maximum Temperature: Gaskets: 250 DEG C, Body: 659 DEG C, Optic: 1400 DEG C, Finish: CLIRVU Coating, NEMA Rating: Type 3/12, Enclosure: IP65, Pull-Out Strength: Up To 1388 LB, UL Listed, CSA Certified, ANSI C37.20.7, EEMACS 14-1, IEC 62271, IEC60068-2-6, IEC60068-2-3, For Outdoor And Indoor