Iowa's Dual Head Cornermatic's automatically inserts and crimps specially designed transverse duct connector (TDC) and transverse duct flange (TDF) style corners in seconds. WE HAVE A SKID OF CORNER THAT CAN SHIP WITH THIS UNIT AT NO CHARGE!!! This machine allows you to do a duct section, eight corners, in about 60 seconds with virtually no physical exertion. Compared to other methods of hand insertion and crimping, it’s a savings of 3 to 6 minutes per section of ductwork depending on size and gauge. This machine is setup to do 5' ductwork all day long. Call 800-753-0393