D3724 Half Glass Hollow Steel Door Door Type 2 Lock Type Mortise Material 18-Gauge Thermal Insulation U-Factor 0.41 Door Opening Height 84 in Door Opening Width 48 in Window Height 29 in Window Width 31 in Thickness 1-3/4 in Agency Compliance ANSI A250.8-1998 UL For Use With Frames 3TFY2 3TFY4 3TFY6 3TFY8 Includes 1/4 in Clear Wire Glass with Safety Film Fire Rated For 45 Minutes 4-7/8 in 37-1/8 in 69-3/8 in 40-1/4 in 84 in