Master Flow 18 in. Starting Collar

The Master Flow 18 in. Starting Collar is suitable for most HVAC applications. It provides a transition from a flat surface like a plenum (made from metal, duct board or insulated) to round pipe or insulated flexible duct. It can be used with duct board, an internally lined or unlined plenum. This galvanized steel starting collar features extra-long tabs to fit most duct board thicknesses.|Connects round pipe or insulated flexible duct to a flat surface to start a duct run|Fits most HVAC types for universal application|Can be used with an internally lined or unlined plenum|Extra-long tabs to fit most duct board thicknesses through 1-1/2 in. (or R-6 value)|Seal seams with code-approved mastic, sealant or duct tape (sold separately)