D3723 Half Glass Hollow Steel Door Door Type 2 Lock Type Mortise Material 18-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 3TFY1 3TFY3 3TFY5 3TFY7 Includes 1/4 in Clear Wire Glass with Safety Film Fire Rated For 45 Minutes 4-7/8 in 35-1/4 in 65-3/8 in 36-1/4 in 80 in