The DSDS is a simple test port kit which facilitates a clever method for properly testing duct smoke detectors from an accessible location per NFPA requirements which calls for test smoke to be properly introduced into the ducts airstream. This kit is made up of a ground-level test port and a ductwork fixed port that connects with a 1" Carlon plenum rated tubing of up to 95' per UL. Tube sold separately.