Some components have multiple connectors that display stacked one above another. When drawing flexible duct from a stacked connector, a Select Connector dialog displays to let you specify which connector to use.
Clicking at the bends in the flexible duct places vertices that you can use to reshape the flexible duct. You can also insert and delete vertices, using options from the flex duct context menu.
Transitions and tees are automatically added to the duct system to facilitate the connections for the flexible duct.