Steel Door, Flush, Door Type 1, Lock Type Cylindrical, Material 18 Gauge Steel, Hand Non Handed, Thermal Insulation U-Factor 0.16, Door Opening Height 80 In., Door Opening Width 36 In., Thickness 1-3/4 In., Agency Compliance UL Fire Rating, For Use With Frames, 3KY80, 3KY81, 3KY72, 3KY73, Includes Polystyrene Core, Closer Reinforcement Channel