Infrared Window Crystal Insert Size 218mm H x 610mm W Viewing Aperture Size 5-29/32 in H x 20-29/32 in W Viewing Aperture Area 79 500 sq mm Window Thickness 3 mm NEMA Rating 4 IP Rating 65 Gasket Maximum Temperature 273 Degrees C (523 Degrees F) Body Maximum Temperature 200 Degrees C (392 Degrees F) Optic Maximum Temperature 325 Degrees C (617 Degrees F) Voltage Range Any Components Aluminum Frame and Cover Body Material Aluminum Includes Installation Instructions