4" stainless steel category II/III universal adapter. Features gasketed connections for a seamless and easy installation. Useful in colder climates to prevent cold air from flowing back into the heat exchanger. The female to female connection fits right on top of the water heater.
Adapts Z-Vent to Laars, Bosch, Nortec, Takagi, Paloma, Rheem, Modine, Rinnai and Reznor flue outlets.