Security Double Doors Door Type 1 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 3TGA3 3TGA5 6-5/8 in 37-5/8 in 68-5/8 in 36-15/16 in