Duct Access Door Door Height 4 in Door Shape Rectangular Door Thickness 1 1/8 in Door Width 8 in Fire Rating Not Rated For Nominal Duct Diameter 7 in 8 in 9 in Hinge Style None Insulation Material Not Applicable Latch Type Thumbscrews Material Thickness 22 ga Maximum Temperature Rating 2 300 Degrees F Mounting Stud Length 2 in Number of Mounting Stud 2 Observation Port Height Not Applicable Observation Port Material Steel Observation Port Width Not Applicable