Master Flow's adjustable elbows are used to make turns in runs of round pipe and flexible duct through 90 degree . They have a sturdy galvanized steel construction and are simple to adjust. They are also crimped on one end to easily fit into a pipe or other fitting of the same diameter. Features: Used to make angular or gradual turns in runs of pipe Adjustable to any angle through 90 degree 30-Gauge, galvanized steel construction Crimped end for easy installation Always seal seams with building code approved sealant or duct tape Always insulate ductwork for greater system efficiency and comfort