NozAll pumpout adapter will make emptying your holding tank as clean, easy and fast as making a trip to the gas station. Made of heavy duty glass filled nylon; Cone shaped design matches exactly with the cone shape of black rubber nozzles found at most pump out stations; Provides an airtight seal between boat deck waste fitting and the pumpout station nozzle; Plastic Adapter screws into deck fitting for a clean connection; 1-1/2" Adapter 1 7/8" Thread O.D.;