This duct Return + Supply can be used with all NXT dehumidifiers to connect your dehumidifier to your HVAC system. The Duct kit replaces the supply and return end cap on you NXT Watchdoog Dehumidifier. Included in the kit are 2 10" duct collars - an inlet and an exhaust and 6 mounting screws - 4 for inlet and 2 for exhaust. 10" ducting is field supplied and required for connecting the duct collars to the supply and return grilles.