Security Double Doors Door Type 3 Lock Type Cylindrical Material 18-gauge steel Hand LHR Thermal Insulation U-Factor 0.41 Door Opening Height 80 in Door Opening Width 60 in Thickness 1-3/4 in Agency Compliance UL 3 Hours Fire Rating For Use With 3TDG1 3TGD3 7-3/8 in 37-5/16 in 67-1/4 in 38-7/16 in