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.