Rugged Quality Construction Designed For Fast Secure Installation Without Using Tools! The DAD Door has been designed to create an airtight seal utilizing a moisture, oil and grease resistant neoprene gasketing between the door to the frame and the frame to the duct. The door panel is constructed out of 24 gauge galvanized steel and filled with a 1” 1-1/2 lb. fiberglass insulation (K factor .26+.03@75°F). The frame is 24 gauge galvanized steel with punched steel tabs along each side, which locks the frame into the ductwork. Smaller frame corner tabs make installation easy. Double camlock latches are used on doors 14” and larger. 12” and smaller have one camlock. Special models and sizes can be fabricated with multiple walls of steel or see-through panels or Cam-Lock only style.