The FlexFlow Elbow maximizes airflow by economically forming any brand and any size of commercial or residential flexible duct into a highly efficient 90a° elbow. Simply strap the one size fits all FlexFlow Elbow over the outer jacket of the flexible duct. It's fast, easy and dramatically less expensive than galvanized elbow installations. Adjustable bands allow the FlexFlow Elbow to fit any size and any brand of flexible duct from 6" to 16"