D3678 Vision Lite Hollow Steel Door Door Type 3 Lock Type Mortise Material 16-Gauge Thermal Insulation U-Factor 0.41 Door Opening Height 80 in Door Opening Width 48 in Window Height 25 in Window Width 31 in Thickness 1-3/4 in Agency Compliance ANSI A250.8-1998 UL For Use With Frames 3TFY9 3TFZ2 3TFZ4 3TFZ6 Includes 1/4 in Clear Wire Glass with Safety Film Fire Rated For 90 Minutes 7-3/8 in 37-5/16 in 67-1/4 in 35-15/16 in 80 in