Oatey 43901 ABS Backwater Valve, 3-Inch, Black Protects low areas or basements from backflow or waste from street sewers Elastomeric seal in quick action flapper ensures a water tight seal Threaded access cap incorporates a neoprene seal for positive sealing and can be tightened or removed by hand 1-1/2-Inch or 2-Inch, 6-Inch x 6-Inch Utility Drain  Fits over 1 1/2-Inch Sch. 40 DWV pipe or into 2-Inch coupling